# How to make a fuel enrichment module for CIS-E



## The_GTi_Art (Jun 3, 2005)

I collected pictures from different places (Some of the pics are not mine, hope the owners don't mind me using them) and i finally was able to make my own FEM, the info i found was insufficient and i still had doubts so i'll add stuff of my own to make this easier.
What you'll need:
1- 1 Relay
2- 1K resistor
(or potentiometer to make it adjustable, i used a 5K potentiometer)
3- Female connectors
4- Tap connector
5- Male and female plugs for the temperature sensor
































































The pics are almost self explanatory of how to make it.
Basically what we're gonna do is get power from the WOT switch (WIDE OPEN THROTTLE) to activate the relay.
All you have to do is disconnect the coolant temp sensor (on 16V engines the temp sensor is located on the right side of the head) and connect the female plug of the FEM and the male plug on the ECU plug.
To test it turn the ignition on and activate the WOT switch, you should be able to hear the relay.
(MODS feel free to edit this for better understanding)


_Modified by The_GTi_Art at 12:56 AM 6-10-2007_


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## wclark (Mar 28, 2001)

*Re: How to make a fuel enrichment module for CIS-E (The_GTi_Art)*

The 16V schematic (above) is a little like the first one I made up a few years ago for my 8V race engine...it switches in a resistor at a selected RPM and WOT (as opposed to whenever the throttle is WOT since going rich down around 2000-3000 is not productive). TT and Autotech offer something similar. The IC is a F:V converter. The fuel demand changes with RPM and load and it seems the open loop table for WOT in the ECU doesnt map this well (at least for a modified 8V and probably for any modified engine). The AFR, if using a fixed resistor inserted into the coolant temp sensor circuit, may only be right in one place in this case (one engine speed and load combination). It is better than stock enrichment as it does decrease AFR across the board, but not enough in my experience (using the values I have seen published in the 1500-200 ohm range). I saw hardly any measurable power increase on a dyno using the above resistor values floating around on the internet...AFR was in the 13.5-14.0 range on a good day. I needed a value of well over 2k for my modified 8V to get anything like 12.5-13:1.
A variation on that, and one I developed and used hillclimbing last year, is to calculate what a given engine needs for "enrichment voltage" at a typical load across the entire RPM range to reach 12.5:1. Then I created an RPM driven log-scale-like output to supply a suitable increasing-voltage-with-RPM to the temp sensor input of the "ECU". This input can be driven by a voltage from 0-5V (a warm coolanttemp resistor usually results in around 1V) or a resistance that pulls the built-in 5V bias down more or less like the temp sensor does. You can get closer to ideal AFR with a log-like curve that tries to correct for the WOT table errors (because of engine mods), but many engines will have a problem area that is hard to dial in since this method also does not actively correct for load. . My 8V counter flow engine, for instance, would go way rich at high RPM until the top end was heavily modified to flow a lot more air (head, intake and exhaust). It is a little complex to reproduce that particular demand decrease (for a near stock intake and header) in an analog circuit. When my engine (with a ported head, OEM intake and header) was using this design I could get the AFR into 12-13:1 up to 5500 but it would drop into the 10:1 range by 6000 which isnt good. When I improved intake and exhaust flow with larger intake runners and a tuned tube header the high RPM AFR improved.
This year I came up with a way to integrate my Innovate LM-1 (analyzer) or an LC-1 into the car so it manages WOT AFR based on WB O2 readings and adjusts WOT enrichment thru the cars temp sensor input to the ECU. It also replaces the stock NB O2 with a suitable simulation so only one sensor needs to be used in the car. This does a much better job of maintaining 12.5:1 across all loads and RPM. In fact the range is more tightly controlled than when the "ECU" is managing AFR at part throttle. My recorded log shows a range of 12.3-12.8 in competition from 3000-7000 RPM for the above engine at WOT in all gears and all loads. 
If anyone is interested in building and tuning either one of the last 2 for themselves, drop me an email, and I will send you a schematic for the hardware. You will need a way to measure AFR beyond what a NB sensor can do while driving to properly tune them for whatever CIS-E engine you have. The log-like analog design will require fair analog circuit design skills to tune, and the LM-1 based design requires the LM-1 or LC-1 from Innovate Motorsports (duh).
I have also worked off and on with an enrichment method suggested by Innovate but have not overcome one problem that may be unique to the Bosch CIS-E. Their method is to use the Analog 1 out of the LM-1/LC-1 set to simulate a stock NB O2 sensor normally and, via a relay, switch in Analog 2 in its place at WOT (The WOT input to the "ECU" must be disconnected so it stays in closed loop operation). The Analog 2 output would be set to output .5V at 12.5:1 AFR but otherwise appears like a normal NB sensor. This works well on Bosch CIS-L engines from reports I have read but the CIS-E "ECU" sees this change as a fault and begins a 10's-of-seconds settling process that results in open loop operation for a while. I speculated the problem is the fact that the switched-in analog output will be registering 1v or 0v as it comes into the circuit since under normal NB profiles 14.7 and 12.5 would be at the extreme ends of a typical NB sensor centered to 12.5 and 14.7 respectively. To try to address the problem thus far I tried widening the "range' of the simulated NB sensors so there was some overlap but either my speculation as to cause is wrong or I havent programmed enough overlap to make the "ECU" happy.



_Modified by wclark at 9:53 PM 6-25-2007_


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## ny_fam (Apr 3, 2004)

*Re: How to make a fuel enrichment module for CIS-E (wclark)*

Both of these posts are very good ideas- this should be tagged so they don't get lost.


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## Volkswoot (Mar 9, 2004)

*Re: How to make a fuel enrichment module for CIS-E (ny_fam)*

I totally loved the one I made. worked great. could definitely tell a difference at WOT.
http://****************.com/smile/emthup.gif


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## BellCityDubber (Jun 13, 2007)

*Re: How to make a fuel enrichment module for CIS-E (Volkswoot)*

I decided to make one, and I used the wrong relay, I just grabbed a relay without looking and had gotten a normally open, with 87 and 87a being the same output.
I now know that this circuit requires a Normally Closed relay.
here's another link just for references sake
http://forums.vwvortex.com/zerothread?id=840484
if you buy a relay from an automotive store, make sure to check the relay schematic and grab one that is a normally closed relay.



_Modified by BellCityDubber at 3:44 PM 4-3-2008_


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## sciroccoboy16v (Sep 4, 2006)

*Re: How to make a fuel enrichment module for CIS-E (The_GTi_Art)*

your first diagram is incorrect
it will make more power but the vehicle will always think that it is running colder than it is
when you go wot with that diagram you open the circuit and the ecu thinks the coolant temp is at minimal value and makes it go way rich
it may make more power but it is not djustable at all
you can replace the resistor with a rheostat and have n adjustable unit
the last one I made with parts from radio shack and pick a part
total cost $5
worked great
before it would get sluggish around 5800rpm
afterwards would run until 6300rpm








with the diagram shown here the ecu sees normal ect value at all times except wide open throttle
when the wot switch is activated the relay activates breaking the circuit
the signal then has to run through the resistor making the resistance higher
indicating cooler temps which means the engine gets more fuel


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## GoKraut (Mar 29, 2005)

*Re: How to make a fuel enrichment module for CIS-E (sciroccoboy16v)*

This one here is off of timbo's site (the second schematic you posted):
I built it the other day - haven't had a chance to do anything with it yet though. http://****************.com/smile/emthdown.gif


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## GoKraut (Mar 29, 2005)

*Re: How to make a fuel enrichment module for CIS-E (GoKraut)*

Going to test it tomorrow....
I finished up the harness.
This works off of a minimum RPM (and WOT)
It has to have both criteria met before it works. That way you don't have the all or nothing effect so many complain about. I'll post up a more advanced version with adjustable enrichment when I get that far...


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## wclark (Mar 28, 2001)

*Re: How to make a fuel enrichment module for CIS-E (GoKraut)*

It looks like the chip being used is the 2907/2917 8-pin version. If this is the case be aware that this one has the input referenced to ground. The coil tach signal is especially noisy around ground and I found false triggers made setting the RPM trip point almost impossible. I had to switch to the LM2907N (14-pin) and reference the input to about 1.2V positive (setting pin 11 to +1.2VDC) to get clear of the ground noise. 
I used to use this chip to turn on fixed added enrichment at about 3500 RPM and still use it as a shift light driver. Here is how it looked then.









_Modified by wclark at 11:06 AM 6-11-2008_

_Modified by wclark at 6:05 PM 6-11-2008_


_Modified by wclark at 6:08 PM 6-11-2008_


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## lilgreydentwagen (Sep 13, 2005)

*Re: How to make a fuel enrichment module for CIS-E (The_GTi_Art)*

SICK!!! how did it work out?? bloody genius!! http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif


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## GoKraut (Mar 29, 2005)

*Re: How to make a fuel enrichment module for CIS-E (lilgreydentwagen)*


_Quote, originally posted by *lilgreydentwagen* »_SICK!!! how did it work out?? bloody genius!! http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif 


Walter's design worked like a charm.


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## lilgreydentwagen (Sep 13, 2005)

*Re: How to make a fuel enrichment module for CIS-E (GoKraut)*

i picked up some 10k pots today from radio shack and i wanna make one of these things. i have some relays and harnesses i grabbed off a benz at pull a part... just cause their shiny







but i'm building a setup for my caddy that could put me over 200 whp on cis-e. what i'm wondering is how do i get it to enrich with this setup based on boost pressure? and how do i hook up a 6th injector on this to fire some more juice when i turn up the boost. i know these systems are fairly simple but i can't do it if i don't know what i need and i can't afford to be dumping money on expensive modules that are mass produced and over priced any links or suggestions, maybe even a parts list to build something like walter has would be very greatly appreciated http://****************.com/smile/emthup.gif


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## wclark (Mar 28, 2001)

*Re: How to make a fuel enrichment module for CIS-E (lilgreydentwagen)*


_Quote, originally posted by *lilgreydentwagen* »_i picked up some 10k pots today from radio shack and i wanna make one of these things. i have some relays and harnesses i grabbed off a benz at pull a part... just cause their shiny







but i'm building a setup for my caddy that could put me over 200 whp on cis-e. what i'm wondering is how do i get it to enrich with this setup based on boost pressure? and how do i hook up a 6th injector on this to fire some more juice when i turn up the boost. i know these systems are fairly simple but i can't do it if i don't know what i need and i can't afford to be dumping money on expensive modules that are mass produced and over priced any links or suggestions, maybe even a parts list to build something like walter has would be very greatly appreciated http://****************.com/smile/emthup.gif 

Maybe someone has done what you are suggesting already and has an answer. Assuming that is not the case might want to try a few things on your own. 
Almost all the modules and DIY enrichment that use the CTS input also trigger by the WOT switch on the throttle. That is fine for the most part but with the turbo is probably not the way to go since you will want enrichment at part throttle too. In fact you may want to disable the WOT switch completely depending on how what I am going to suggest works out.
Based on my observations of the 16V CIS-E in my car I believe the electronics uses the coolant temp resistance input all the time so when the engine is first started cold it targets a Lambda of around .85. The electronics pretty quickly increases that to lambda 1.00. My point is it might be possible and for a turbo, practical to fool the electronics at any throttle position to richen the mix by changing the CTS input.
A simple way to test the idea is to put one of your pots in place of the CTS sensor and monitor AFR at various pot settings and see if it does indeed force the mix to operate about richer points than stoichiometric.
If this is true then you go a couple ways to make it work for you. Either a simple switched-in pot, perhaps triggered by a pressure switch, or a voltage generated proportional to vacuum/boost. The first is simple but may not deliver a consistent AFR or one that varies appropriately with amount of boost and load. The second one is more complex but could smoothly transition fueling from a steady state lambda 1.0 at light loads to .8-.85 as load and boost increase.
The more complex solution also might require using a wideband O2 sensor and suitable conversion electronics. A narrow band O2 goes very non-linear either side of lambda 1.0 making control in the.85 range difficult and a wide band does not (but it must be scaled properly for the CIS-E electronics). My experience with this is mainly observing my CIS-E which IS fed by a suitably scaled wide band sensor signal.


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## lilgreydentwagen (Sep 13, 2005)

*Re: How to make a fuel enrichment module for CIS-E (wclark)*

wow very informative. http://****************.com/smile/emthup.gif 
any ideas as to where i might find a decently priced wideband? i was thinking about getting one anyway. 
also is there a way i could maybe use a map sensor to control flow in place of the cts? i don't have the funds to dump in a stand alone right now and i really suffer from terminal uniqueness and would like to see how much power i can squeeze out of this system. i may have bitten off a little more than i can chew with this project cause time is of the essence. i'm moving in less than 2 weeks and i'm confident i can get this working but i wanna do it right so i don't break anything... and i don't wanna pay some greaseball tow truck driver 400 bucks to tow it either. i appreciate your help greatly. here's what i have as of now the pots, relays and everything i need to fool the comp. i'm running audi 200 turbo injectors. a volvo 7 somethinsomethin fuel pump k26 turbo stock wastegate (for that setup) and the jetronic computer/ knock box. i'm almost wondering if this setup will work without messing arount with the brains too badly? i just don't want to lean out in the top end cause that is where i'm used to driving these cars and i don't wanna blow any holes in my pistons in the middle of bfe where i'm moving to


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## wclark (Mar 28, 2001)

*Re: How to make a fuel enrichment module for CIS-E (lilgreydentwagen)*

In 2 weeks, unless you can spend all that time on this and have a solid electronics background you are biting off too much to get done. Assuming you will go with a wideband anyway (even if you dont initially use it to drive the CTS input)...
You need to define "decently priced". I would go with the Innovate Technology LC-1 at about $200. http://www.innovatemotorsports...1.php 
You can connect this to one of their AFR meters, or to a PC/laptop for monitoring, logging and tuning. It has 2 programmable analog outputs, one of which can be used to "simulate" a narrow band sensor for the engine electronics in place of the stock narrow band. Of course this output is going to be linear across a wide lambda range rather than switching rich/lean like a narrow band around stoichiometric. My experience with the VW version of the KE-Jet for the 16V is it is OK with the more linear input (scaled to the .1-.9V range of a NB) and it manages the AFR with less of or the same lean/rich switching that is exhibited with a NB depending on how steep you program in the lambda versus voltage slope out of the LC-1. The second analog output can be programmed and used later on to feed a 1-3V signal in place of the CTS sensor when you want to drive the lambda to a new value. This could be anything from a fixed voltage in place of a pot to a voltage that varies based on actual measured lambda to help the ECU maintain an enriched value you want. 
Point of fact. The CTS sensor or a pot loads down the CTS input to the ECU to create an input voltage. The input of the ECU is internally tied a 5V level thru a 5K resistor, so an infinite value of load resistance yields 5V, 5K ohms external load yields 2.5V, and 0 ohms yields 0V. You can easily substitute a controlled external voltage source capable of sourcing at least 1ma (or more accurately sinking 1ma). I have found the normal "warmed up" voltage with the CTS sensor connected is about 1.08V. I have also found that with my both NA 16V and NA 8V before that I needed no more than 2.5V to drive the lambda to .85 at any altitude, RPM and load.



_Modified by wclark at 1:53 PM 9-4-2008_


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## fartech (Aug 18, 2008)

*Re: How to make a fuel enrichment module for CIS-E (wclark)*

Im am intrested in the specific settings you used with your LC-1, and how the motor responded. I have installed a spare LC-1 in my cabby but it had a bad sensor so am awaiting a new one.


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## wclark (Mar 28, 2001)

*Re: How to make a fuel enrichment module for CIS-E (fartech)*

I will check where they are right now and post them sometime today along with comments. By the way I am using an LM-1 because I wanted the extra features.

I have the "O2" sensor output set to: 1.0V.85L .10V/1.15L
And I have the CTS drive set to: 1.0V/.80L 3.0V/.93L
My experience is that narrowing the Lambda range on the "O2" output tightens up the control of AFR a little.
With the CTS output I experimented a LOT with settings. I found a range of about 1-2.5V worked well for my 8V and 1-3V works better for the 16V. The Lambda values were chosen to be roughtly equidistant from the target Lambda at WOT. When connected, up this creates a feedback closed loop that actively drives Lambda. One problem with it is that if you try to set the amount of "feedback" (the slope of the output) to steep the CIS-E "system" will oscillate - overshooting the target Lambda repeatedly, especially noticable when there is no engine load (such as testing in the shop). Decreasing the slope of the output slows the system response (allowing more variation in Lambda) but it prevents the oscillation. Under load (in my case Vt. hilllcimbs, which tend to be mostly WOT and 10-20 degree grades) my data shows an initial overshoot into the .8 range as the WOT switch activates but that lasts only a couple 10ths of a second then it shows pretty smooth control around .86 until I lift (and the WOT switch drops out), then the Lambda goes lean or rich for a moment depending on whether the throttle is closed or partially open - that part is up to the ECU - and it works its way back toward 1.0. 
fartech - PM me your email and I will send you a log (Logworks) file from one of my runs at the last hilllcimb. As they say a picture is worth a thousand words.


_Modified by wclark at 9:22 AM 9-5-2008_


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## lilgreydentwagen (Sep 13, 2005)

*Re: How to make a fuel enrichment module for CIS-E (wclark)*

wow very informative. http://****************.com/smile/emthup.gif 
any ideas as to where i might find a decently priced wideband? i was thinking about getting one anyway. 
also is there a way i could maybe use a map sensor to control flow in place of the cts? i don't have the funds to dump in a stand alone right now and i really suffer from terminal uniqueness and would like to see how much power i can squeeze out of this system. i may have bitten off a little more than i can chew with this project cause time is of the essence. i'm moving in less than 2 weeks and i'm confident i can get this working but i wanna do it right so i don't break anything... and i don't wanna pay some greaseball tow truck driver 400 bucks to tow it either. i appreciate your help greatly. here's what i have as of now the pots, relays and everything i need to fool the comp. i'm running audi 200 turbo injectors. a volvo 7 somethinsomethin fuel pump k26 turbo stock wastegate (for that setup) and the jetronic computer/ knock box. i'm almost wondering if this setup will work without messing arount with the brains too badly? i just don't want to lean out in the top end cause that is where i'm used to driving these cars and i don't wanna blow any holes in my pistons in the middle of bfe where i'm moving to


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## lilgreydentwagen (Sep 13, 2005)

*Re: How to make a fuel enrichment module for CIS-E (lilgreydentwagen)*

ok. so i got a few things out of the way still haven't gotten the truck running i'm trying to find adapters for my fuel injectors unfortunately for me i can't modify my lines to make the audi ends with the correct 10 x 1 female connectors to work on my stock lines so i may bag the idea for now and run stockers with a 6th injector with a boost switch set to kick in at 5 psi to activate the injector. also i have an fpr from a saab turbo that i think is set to 2 bar... i could be wrong but it will piggyback the stock fpr with an adapter then t off to the 6th injector. color me crazy but it might just work till i can afford the lm-1


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## fartech (Aug 18, 2008)

*Re: How to make a fuel enrichment module for CIS-E (wclark)*

Thanks for the log file! I have gotten mine installed in the cabby.
I set the LC1 to: 1.1v=13.1afr and .103v=15.53 & 1/12sec averaging.
Stock settings and no averaging made the cars AFR swing too much and stay richer. The settings above netted me an AFR that only varied +/-.1AFR at an idle. I still have to do some more testing in a cruise state. http://****************.com/smile/emthup.gif


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## VWguyBruce (Dec 3, 1999)

Thanks for the post and the info.
I'm in a situation where I need something quick and dirty. I'm prepping an 86 GLi for the $2008 Grassroots Motorsports Challenge. I've run out of time for the turbo install and now am scrambling to improve the power of the stock motor in a hurry. My only mods to the motor will be 35hp shot of NOS and AC/PS removed.
Will the basic circuit that The_GTi_Art or sciroccoboy16v posted work well enough in a pinch? I will likely use the POT for adjustability.
Thanks in advance...


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## wclark (Mar 28, 2001)

*Re: (VWguyBruce)*


_Quote, originally posted by *VWguyBruce* »_Thanks for the post and the info.
I'm in a situation where I need something quick and dirty. I'm prepping an 86 GLi for the $2008 Grassroots Motorsports Challenge. I've run out of time for the turbo install and now am scrambling to improve the power of the stock motor in a hurry. My only mods to the motor will be 35hp shot of NOS and AC/PS removed.
Will the basic circuit that The_GTi_Art or sciroccoboy16v posted work well enough in a pinch? I will likely use the POT for adjustability.
Thanks in advance...

Yes. Of course you will want the pot to be switched in when the NO comes on and the pot set based on your monitoring and setting of AFR with a wideband and/or EGT under actual load. As the correct enrichment will vary with air temperature, humidity,air pressure, load and RPM (less so with a stock engine and Oxy CU), you should plan a way to set this as close to the actual running (the drag race portion) as possible. I assume tuning costs (buying and using wideband monitors, EGT sensors, dyno time) are not counted in the $2008 (unless permanently tied into the car) so stand alone stuff like the Innovate LM-1 - using welded in bungs to the exhaust manifold and downpipe - would be appropriate.


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## VWguyBruce (Dec 3, 1999)

I've got a JAW kit to assemble but may not have the time. Had a minor incident with the car falling off the jackstands on Sunday and poking a hole in the fuel pump housing. Strangely the junkyard had one. This put us a little behind schedule. 8 Days to go.
Got all the stuff for my circuit at the junkyard, maybe I should take the time to get my JAW together...
The NOS system has a WOT switch, I wonder if I could just use the factory part to trigger the solenoids, hmmm. We're going to install the NOS tomorrow night.
Anything that is attached to the car when it runs down the track/autox counts toward your budget. I'm way under budget this year so I've got some wiggle room.

_Modified by VWguyBruce at 1:54 PM 9-23-2008_


_Modified by VWguyBruce at 2:05 PM 9-23-2008_


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## wclark (Mar 28, 2001)

*Re: (VWguyBruce)*

I am not too familiar JAW kit but assuming it is not controlling anything, you shouldnt need it in the car for competitive runs unless it actively manages something, just for test runs to get the AFR set.
The WOT switch on the throttle body supplies +12V when active. It easily drives typical Bosch relay coils so could work for you. If your NOS uses a low impedance solenoid you may want to put a Bosch relay between the WOT switch and that solenoid or the current draw from the solenoid could toast the switch. I wouldnt go over 1A drain on that switch. 


_Modified by wclark at 11:23 AM 9-24-2008_


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## VWguyBruce (Dec 3, 1999)

There is a relay in the kit. I hope to tackle all this tonight. I fought an axle for 5 hours last night, stupid 30 minute jobs...


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## wclark (Mar 28, 2001)

*Re: (VWguyBruce)*


_Quote, originally posted by *VWguyBruce* »_There is a relay in the kit. I hope to tackle all this tonight. I fought an axle for 5 hours last night, stupid 30 minute jobs...

I hear that. Since my GTI has been a race/garage queen since I tore it completely down and built it back up a few years ago so it comes apart and goes together like a new car. About once a year I seem to inherit a parts car (so far 3 A2 and a B3) and am re-introduced to the joys of working on a 20 year old former daily driver.


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## AceOvSpadez (Nov 26, 2000)

*Re: How to make a fuel enrichment module for CIS-E (sciroccoboy16v)*


_Quote, originally posted by *The_GTi_Art* »_










_Quote, originally posted by *sciroccoboy16v* »_your first diagram is incorrect
it will make more power but the vehicle will always think that it is running colder than it is
when you go wot with that diagram you open the circuit and the ecu thinks the coolant temp is at minimal value and makes it go way rich
it may make more power but it is not djustable at all
you can replace the resistor with a rheostat and have n adjustable unit
the last one I made with parts from radio shack and pick a part
total cost $5
worked great
before it would get sluggish around 5800rpm
afterwards would run until 6300rpm








with the diagram shown here the ecu sees normal ect value at all times except wide open throttle
when the wot switch is activated the relay activates breaking the circuit
the signal then has to run through the resistor making the resistance higher
indicating cooler temps which means the engine gets more fuel


The 1st diagragm IS correct!! You have not changed anything by relocating that resistor, they are still connected to the exact same pins. 
I think the picture may look misleading because of where the resistor is drawn making it appear as if the resistor will move to pin 87 when powered up.
Also, you changed pin 85 to ground, but notice 86 is also going to ground. That relay isnt ever going to do anything



_Modified by AceOvSpadez at 12:15 PM 3-9-2009_


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## rorin8v (Oct 15, 2007)

the one made at the top with the relay will it work for the
cars that have cis-e with out the wot switch?
i swaped my throttle to one with the switch.


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## wclark (Mar 28, 2001)

*Re: (rorin8v)*


_Quote, originally posted by *rorin8v* »_the one made at the top with the relay will it work for the
cars that have cis-e with out the wot switch?
i swaped my throttle to one with the switch.

I was not aware that a CIS-E existed without a WOT switch. But either way, yes, for a system like the relay designs above to work, something akin to a WOT switch is required.


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## bubba_vw (Dec 3, 2008)

what about making one for CIS-L??


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## chois (May 12, 2000)

I ended up simplifying the one I use on my IT car. I eliminated the coolant temperature sensor completely, as I am only concerned with how it runs when properly warmed up, and this removed potentail failure points in extra wiring and sensors. I just drop the signal through a potentiometer to ground and set the resistance on the dyno for best results. I then put a mechanical limit switch on the pedal box that is normally closed, and opens at about 60% throttle. No WOTS, no relays, no connections in the engine bay.
Simpler is better.
I also wired in a momentary push button to activate the cold start injector to get it going for cold early morning track sessions.
I got all I think I can out of the system at this point, and will be putting together a Megasquirt system running stock digi components to see if I can get more 'area under the curve' with more tuneable fuel and ignition tables. We'll see....


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## EL DRIFTO (Jul 11, 2004)

*Re: (bubba_vw)*

cis L can be richened up a little by closing the "thermo switch"
it basically ignores o2 at that point, sends cold/rich signal to cisl freq valve. 
same as grounding the o2 wire
it seems like keeping thermoswitch closed helped in the winter, while leaving my full throttle switch disconnected help in 100 degree days


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## BSD (Jul 8, 2008)

Closing the thermo switch made my car impossible to idle.. it'd die instantly.. but it had a good top end!








Steve-


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## johnnyGO (Feb 23, 2009)

*Re: How to make a fuel enrichment module for CIS-E (GoKraut)*

Would you happen to have the schematic and parts list to your version GoKraut? 


_Modified by johnnyGO at 8:28 AM 3-19-2009_


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## Canadian V-Dub (Feb 10, 2009)

Awesome news!
Any chance some of the pics can be resized? I'm using a 21.6" monitor and having to side-scroll hardcore. It's quite inconvenient to read efficiently.
Keep up the good work!


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## EL DRIFTO (Jul 11, 2004)

*Re: (BSD)*


_Quote, originally posted by *BSD* »_Closing the thermo switch made my car impossible to idle.. it'd die instantly.. but it had a good top end!








Steve-

then turn down the idle mixture, switch on, until it idles


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## johnnyGO (Feb 23, 2009)

This may be a dumb question but here it goes anyways. What about adjusting the WOT switch to engage before WOT? My powerband starts about 3800-4k and levels off before I even get the pedal pinned.


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## chois (May 12, 2000)

I do that with my limit switch mount at the gas pedal. I have bent the actuator at the WOT switch in the past as well to make it click in sooner.


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## johnnyGO (Feb 23, 2009)

*Re: (chois)*

OK cool, so its not a bad thing to do then?
And when did you make yours engage, 3/4 pedal, 1/2 pedal, ect..?


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## chois (May 12, 2000)

*Re: (chois)*


_Quote, originally posted by *chois* »_ I then put a mechanical limit switch on the pedal box that is normally closed, and opens at about 60% throttle.


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## wclark (Mar 28, 2001)

*Re: (johnnyGO)*

Mine comes on just after the second TB butterfly opens.
With an enrichment "module" that doesnt actively manage fuel delivery you risk over enriching if it some on at too low a throttle opening. That wont hurt anything in the engine but it dumps black smoke, can degrade performance and wastes a lot of fuel.


_Modified by wclark at 8:49 PM 3-19-2009_


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## johnnyGO (Feb 23, 2009)

*Re: (wclark)*

Roger that... I was just thinking about it while I was going through this topic, since in a sence the module is basicly doing the same thing as the WOT switch ( IE: richening ) except the module can be adjusted.
That also brings up another point, wont the module make the car way to rich at full throttle or when the WOT switch is engaged or does the module over ride the WOT?


_Modified by johnnyGO at 10:10 PM 3-19-2009_


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## chois (May 12, 2000)

I have in a pinch run it off a manual switch on the dash (WOT switch bracket broke). I was able to set the system up so that it worked fine as long as I kept things above 4300 to just leave it on. But yeah not ideal, just something you could do in a pinch.


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## wclark (Mar 28, 2001)

*How these work with VW/Bosch CIS-E*


_Quote, originally posted by *johnnyGO* »_Roger that... I was just thinking about it while I was going through this topic, since in a sence the module is basicly doing the same thing as the WOT switch ( IE: richening ) except the module can be adjusted.
That also brings up another point, wont the module make the car way to rich at full throttle or when the WOT switch is engaged or does the module over ride the WOT?

_Modified by johnnyGO at 10:10 PM 3-19-2009_

The "modules" that connect to the CTS work this way...
At WOT the ECU operates open loop - that is, it no longer uses the O2 sensor input to drive fuel management. Instead the ECU refers to an internal algorithm that generates predefined currents for the DPR based on load (vacuum), engine temperature, and RPM. This factory enrichment is only slightly rich (Lambda around .95) when the engine is warm and seems intended to help prevent pinging and not so much to produce max power - which would require Lambdas around .85. 
The above enrichment modules use the WOT switch output voltage to switch in a higher resistance to the CTS ECU input, making the ECU think the engine is colder and it in turn calling for higher DPR currents. This method of fooling the ECU can drive the Lambda well below the .85 Lambda power optimum even with highly modified engines. I have seen lambdas of below .7 (about 10:1) and know the control had range to go much further. Somewhere below .7 one risks washing down the cylinder walls with fuel because it will not all burn, risking ring wear and fuel in the crankcase.
According to Probst in his book, some of the Bosch KE-Jet ECU's will not respond to sudden changes to the CTS input and this technique will not work. My experience with the KE-Jet modules for the RD and PL engines is it works.

In my experience the vacuum input has a small effect on ECU enrichment, and it is not enough to fullly compensate for the decreased fuel enrichment needs of small throttle openings when WOT is switched on. 
I also found that a given resistor value will not produce a constant Lambda across the RPM range. It isnt too far off on a stock engine but as modifications are added in (cams, valves, P&P intakes and exhausts) the error increases. Thus, with my race RD engine I could dial in my desired .85 for a single RPM on a given day at a particular altitude (I hillclimb and the car usually changes elevation a thousand feet, more or less, in a run) but it was in error otherwise...sometimes by more than .15. The technique of using a pot or even a pre-determined fixed value resistor (a.k.a. the TT module) can work real well for road racing where a fully warmed engine is kept in a narrow power band at a more or less constant elevation. And it may even be set up to be tweaked by the driver from the cockpit using an EGT sensor on the long straights. 
The TT module uses a safe value when selected per their directions that more or less works across a wide range of conditions because it doesnt try to enrich too much (somewhere above .85).
Dialing in a suitable resistor value for a given DIY project that gets Lambda as near to .85 as is safe (no excursion below .7 or over .95) requires a wideband O2 sensor and monitor/logger - or better yet some dyno time. Having had an Innovate LM-1 for a few years now I consider it as valuable as a good helmet and the shop manual. Once dialed in, some racers will note the EGT and strive to maintain that temp thru small adjustments of the pot while racing.



_Modified by wclark at 12:26 PM 3-20-2009_


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## johnnyGO (Feb 23, 2009)

WOW, thanks much wclark. Very nicely said.
I myself have been looking at widebands but I think I need to understand CIS-E a bit more before I drop the $200 on one, other wise I think it might be a waste.
Thanks again.


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## wclark (Mar 28, 2001)

*Re: (johnnyGO)*

By the way, I use my LM-1 in the race car all the time. Ican remove it and have a spare WB sensor for other projects, but it goes back in the GTI when that is done. I data log each run - it uses the RPM converter and that lets me analyze, RPM, EGT, CTS drive voltage, Oil pressure, and Coolant temp after each run.
The LM-1 is now the control for the fuel enrichment. The WB sensor replaced the NB in the car. The 2 analog outputs are used to 1) simulate a NB for the ECU and 2) generate a control voltage that gets switched into the ECU under WOT. The voltage to the ECU actively drives Lambda to .85 anytime the WOT switch is on, pretty much no matter the load, RPM, elevation, temps or anything else. The Innovate LC-1 would do the same thing, minus the data logging.


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## johnnyGO (Feb 23, 2009)

*Re: (wclark)*

So would you say a WB is the "Chip" in the CIS world? You say that one of the outputs is to control the voltage but how is that adjustable from the WB, is it programmable?
Sorry for all the questions, Im just tring to wrap my head around this. Alot of articals about CIS talk about its simplicity, I have no frickin idea how they came to that conclusion








Whats the reason behind no one playing with the ECU itself (IE: chip )? Now tell me if Im wrong but CIS such as mine on my audi ( CIS-E III ) has a similar ECU as a EFI car, meaning it plays with Air/Fuel, lambda, ect... the only diff is the fuel delivery, so again why hasint there been a chip made or ECU mods?
thanks again


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## wclark (Mar 28, 2001)

*Re: (johnnyGO)*


_Quote, originally posted by *johnnyGO* »_So would you say a WB is the "Chip" in the CIS world? You say that one of the outputs is to control the voltage but how is that adjustable from the WB, is it programmable?

Not so much as a chip as a sort of piggyback add-on that fools with ECU inputs. Sort of like some boost controllers on current turbo cars.
The LM-1 has 2 programmable analog outputs. By programmable I mean you can specify a voltage/lambda at one end of a slope and a voltage/lambda at the other end so the output varies within these limits based on measured lambda. I set one to mimic a NB sensor so the KE-Jet is happy while in closed loop operation and the other is a range of voltage that mimics a variable resistor that is changing constantly based on how far off .85 the measured lambda is at WOT. As it happens the CTS input to the ECU has a current limited 5V that is loaded by the CTS resistor so the lower the resistance the lower the voltage. It is possible to simply supply a 0-5V level to this input (in reality the range needed is 1-3V) to drive the Lambda while at WOT.
FWIW. I know the chief of Innovate was able to use the 2 analog outputs of the LM-1 to drive the O2 sensor input of the CIS-L ECU thru a relay that switched between the two, using the - disconnected to the ECU - WOT switch. One input was normal O2 voltage levels versus lambda (.5v=1.0) and the other was scaled lambda versus voltage to move the lambda to .5V=.85. That wont work on the CIS-E because the processor sees a glitch or something when switched that puts the ECU into some limp mode or open loop for a handful of seconds before accepting the "new" signal. I was never able to resolve this using analog circuits that prevented apparent glitches and limited the magnitude of signal during transitions between analog outputs. I never tried building a digital processor filter that probably could be programmed to look "normal" during transitions between sensor levels and actually be normal in between. 

_Quote, originally posted by *johnnyGO* »_Sorry for all the questions, Im just tring to wrap my head around this. Alot of articals about CIS talk about its simplicity, I have no frickin idea how they came to that conclusion









It really is fairly simple - well it was when it was CIS-basic. It got more and more sophisticated as emissions became more restricted. 

_Quote, originally posted by *johnnyGO* »_Whats the reason behind no one playing with the ECU itself (IE: chip )? Now tell me if Im wrong but CIS such as mine on my audi ( CIS-E III ) has a similar ECU as a EFI car, meaning it plays with Air/Fuel, lambda, ect... the only diff is the fuel delivery, so again why hasint there been a chip made or ECU mods?
thanks again

Basically no one seems to have been sufficiently motivated to reverse engineer the module to the degree needed. Parts may also be an issue at it appears there are some Bosch specific components. 


_Modified by wclark at 5:00 PM 3-20-2009_


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## johnnyGO (Feb 23, 2009)

Ahhh, the WB makes sence now.

_Quote »_Basically no one seems to have been sufficiently motivated to reverse engineer the module to the degree needed. Parts may also be an issue at it appears there are some Bosch specific components. 

Maybe all of us CIS-E guys should start a fund to hire a guy or Co. to make us a tunable ECU (Plug and play like the EFI cars)


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## ellocolindo (Jan 15, 2010)

can this principle be aplied to a volvo 240 turbo distributor head in to a 16v aba turbo with a audi v8 head on top af a obd 1 aba short block? anyone have one already made to have a log-type table? i want to buy something made ; ready to plug and play.
noob at electronic stuff here...


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## tjyak50 (Aug 30, 2010)

Sorry to come in late to the game.

I have a 1988 Mercedes with CIS-E and I have a Wideband O2 installed for watching the car.

It is my experience that I can tune the CO adjustment and the EHA adjustment to get better WOT AFR.

Problem #1) is the system gets progressively leaner with higher RPM
Problem #2) changes in outside air temp seem to change my settings.

Is this the same for everyone and hence the reason for the spoof box?


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## Brunke_Stunkelmyer (Sep 21, 2009)

tjyak50 said:


> Sorry to come in late to the game.
> 
> I have a 1988 Mercedes with CIS-E and I have a Wideband O2 installed for watching the car.
> 
> ...


Mines going towards a turbo CIS build.


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## oldsklaudidub (Aug 29, 2006)

*ID fuel enrichment module please*

I've been holding off on this post trying to ID this module for a long time but now I must ask for help.

This module came off a 16v Scirocco

This module has six wires (it appears to be ethernet cable)

I have no clue as to what wire is supposed to go to what?
(expect for what is instructed for the connections in the thread)
white wire=?
blue wire=?
brown wire=?
red wire=?
green wire=?
orange wire=?

The OUAZ-SS-112D is a form C relay: OUAZ-SS-112D,900 Tyco Electronics


Chip on there (LM2907) is a frequency to voltage converter, often used for tachos and such. 

My guess is that at a certain engine speed (controlled by the dip switches, I suppose) it flips the relay, but for what purpose I don't know.. 

*Does anyone have idea which module this is and what wire goes to what? TYIA*
Larger picture of bellow


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## URIN 2ND (Oct 29, 2001)

No clue...I'm wondering what the dip switches are for.

Maybe it's a garage door opener. :laugh::thumbup:


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## vdubridah (Oct 20, 2012)

where can I source a female coolant temp sens plug? is there a certain model that will have em? i tried picknpull but all mk2 n 3 didnt have that plug.... i did find the male one though....:banghead:


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## vdubridah (Oct 20, 2012)

vdubridah said:


> where can I source a female coolant temp sens plug? is there a certain model that will have em? i tried picknpull but all mk2 n 3 didnt have that plug.... i did find the male one though....:banghead:


so i found all connectors, i just need to source the proper relay. anyone know a car they come stock in? or know where to get a relay brand new?


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## Scirocco16 (Feb 4, 2012)

Ok, I've been reading this info, and as my car has a mostly stock 16v (just a header), I'd like to experiment with a simple version of this. From what I read, a stock engine should stay close to an ideal AFR through the higher RPM with the simple potentiometer/relay system connected to WOT and coolant temp sensors, right? I'd like to make the module "transparent" in the lower RPMs though so it doesn't over-enrich and bog down. So how would I make such a thing kick in with extra ECT resistance at a selected rpm value, say 4000 rpms?


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## WaterWheels (Aug 14, 2005)

To make a long story short, you use it in conjunction with the WOT switch on the throttle body. To make the story even shorter and much nicer go to Autotech or TechTonic and look at their units which are already made for you. The Autotech one is adjustable for future up-grades if you do any but if I remember the TechTonic one is not. I know building youre own would be fun and a talking point, but they don't cost all that much and have everything you need. Plus they maybe look better then a home made one too.


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## Scirocco16 (Feb 4, 2012)

If the autotech and TT ones were cheaper I'd consider them. If those are only taking input from the WOT switch, then it would take $10 and 20 min. to make one that does the same thing. With a potentiometer it would be adjustable also. 

It's not productive to enrich the mixture at low rpms tho, soI'm just wondering how to make it switch on at a specified rpm, along with the WOT input, so Im not enriching the mixture at WOT at 2000 rpms. 

If the autotech one has this feature, then I may be interested after all.


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## WaterWheels (Aug 14, 2005)

Forgive me for my suggesting that spending around $150 was the smarter way to do this, but I view things a little differently than others sometimes. Maybe you’re short on cash or maybe you just want to make it yourself for some reason or another, that’s fine. If that’s the case then there is a small wiring diagram earlier in this string which should be enough for you to do the job. There is also information to be found by searching the Internet. For myself, I like things to look as much like it came from the factory as possible and if that’s not possible I want it to look as good as possible. Not everyone can build a wiring harness to appear factory on a small budget or even know how and where to get the parts for that matter. I also like to think *MY* time is worth something so I include that into deciding whether to build or buy. Then there is the availability factor I think about, if it’s already there for the having then why should I use up my time or wait for things to be sent to me when I could be doing other things.


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## vdubridah (Oct 20, 2012)

Scirocco16 said:


> Ok, I've been reading this info, and as my car has a mostly stock 16v (just a header), I'd like to experiment with a simple version of this. From what I read, a stock engine should stay close to an ideal AFR through the higher RPM with the simple potentiometer/relay system connected to WOT and coolant temp sensors, right? I'd like to make the module "transparent" in the lower RPMs though so it doesn't over-enrich and bog down. So how would I make such a thing kick in with extra ECT resistance at a selected rpm value, say 4000 rpms?


 i made my own module, looks like it came with the car from factory. my 16V just about is bone stock. only upgrades are: a/c and p/s delete, k&n air filter, and neuspeed spark plug cables. i felt an improvement with the FEM. i have raceland header that im going to put in soon. you can make a FEM that requires a certain rpm and wot to turn on the module.


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## Scirocco16 (Feb 4, 2012)

Thanks for the input guys. I know how to make one using wot as the input, just wondering how the rpm signal works?


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## simon-says (Oct 21, 2007)

*Bump for more CIS-L systems using the LC1*

Is there any wiring diagrams on how to hook up the LC1 to the ECU and whats settings to program it?


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