# Tuning CIS -using a wideband controller



## ny_fam (Apr 3, 2004)

Here is a short report on a CIS upgrade I did a few months ago and it turned out very well so I figured I'd share the results.
If you Don't want to go all the way to megasquirt you can go half way - keep CIS and add computer controlled tune-ability. For less than $300 you can add a wide band controller to your CIS Lambda setup(k-jet). Then you can use your laptop to set the CIS fuel ratio(s) to find the best tune. I've found this to be the best bolt on I've done to my GTI yet. This mod really made all the other upgrades work very well. 
You'll need a Innovate MTX-L with O2 sensor controller $199 from DIY Autotune(or similar PLX unit) and about $50 or so in wiring connectors and 2 auto relays. I'm not the first to do this upgrade done back in 2005 by a guy that seems to work at Innovate Motor Sports http://www.innovatemotorsports.com/forums/showthread.php?t=1520

http://www.diyautotune.com/catalog/innovate-mtxl-gauge-sensor-controller-3844-p-467.html
Gauge fits perfectly in the GTI console gauge pod in place of the redundant clock.









Note where NA motors make the most power(generally speaking more compression will use more fuel). The stock GTI lambda fuel ratio tends to run around 10:1 at WOT. I have found and others confirmed that 13.2 -13.5 is where these VW NA engines make the most power. So the Stock Lamba at WOT is wasting fuel, and not making as much power as it can.

Installed








Cheers
ny_fam


----------



## ziddey (Apr 16, 2006)

Am I remembering correctly that this doesn't work right for cis-e if you're to use the wot switch to switch from a stoich/lean afr to rich signal? It causes the ECU to disregard lambda for a few seconds or something like that? I wonder if actually tripping the WOT switch and bringing it to open loop for a split second while the output is changed would solve this.

I'd imagine a good mod would be to use a TPS or otherwise have the switch triggered at say half throttle to switch from lean/cruise mode to enrichment instead of at WOT.


----------



## ny_fam (Apr 3, 2004)

I can't speak for CIS-e, but does work for CIS lambda. We modified our WOT switch so it is switched when the larger secondary throttle plate starts to open, so its more like you describe.

I know that others have used a similar setup for CIS-E but I don't know the details, I'm aware of CIS-E for racing applications where a WOT switch may not be used any more.


----------



## Danger1523 (Dec 16, 2011)

I believe I have CIS-E so I don't know how this would apply to such. How could you alter the compression ratio up without changing pistons and head etc. Thanks


----------



## ny_fam (Apr 3, 2004)

There are after market head gaskets that can bump the compression a 1/2 a point.


----------



## Road Boss (Jul 16, 2004)

I need to keep this in mind once I had my charger to my CIS.


----------



## ellocolindo (Jan 15, 2010)

i have cis-e motronic in my 91 passat now. i am boosting it; and gather all the CIS system form a volvo 240t to use. will the volvo set-up fall in the CIS-lambda definition?


----------



## ny_fam (Apr 3, 2004)

If the fuel distributor uses a frequency valve then yes.


----------



## ellocolindo (Jan 15, 2010)

yes it has a frequency valve. i do not know if i will use it...


----------



## spddemon313 (Nov 15, 2006)

well i have a few quesitons if you all don't mind helping out a noob to engine tuning. i just got my car up and running after an extensive 3 1/2 year rebuild. i'm hoping to eventually switch to carbs so i can clean up the bay. i'll be on stock CIS-lambda for a little while though, at least until the break-in period is over for my engine.

so i've been looking at all sorts of engine tuning threads and tool and tips and these wideband controllers kee surfacing. first off, would you mind telling me how you hooked up your wideband to your car...as in which wires go where? i know one goes to a laptop for datalogging and tuning, but do the others all hook up to the O2 sensor control until under the glove box?
also, if i do end up switching to carbs, that means the entire o2 control unit is deleted, will i then just run the wires from the wideband into the passenger compartment to the gauge?

second question, what can a wideband do that a simple gauge on the stock single wire o2 sensor can't? other than instant tuning off your laptop of course. 

just trying to figure out if it's worth the $209+tax+shipping to go with a wideband if this is only a daily driver...yes i want good results and performance, but this isn't a race car

thanks for reading, easy on the slams i'm new to this tunign bizz


----------



## ny_fam (Apr 3, 2004)

The controller gets programmed by the laptop, then in normal operation you don't need the laptop connected. The controller will allow you to set the fuel mixture where you want, something you can't do with CIS- lambda (K-Jet).
Once your on carbs you use the wideband as just a gauge to tune the carbs.
The innovate MTX-L is both the gauge and controller in one. So you just need to find a place to mount the gauge. The wiring isn't that complex to setup, easier to install. You'll need power, ground, switched power, a 3/8" hole in firewall for wires to pass through. Send me a PM about the wiring details.
For what its worth - a properly tuned 8v on CIS should be able to make in the range of 110-120 hp, with just bolt ons and a good tune. I believe this is part of that good tune.
Cheers


----------



## spddemon313 (Nov 15, 2006)

ny_fam said:


> The controller gets programmed by the laptop, then in normal operation you don't need the laptop connected. The controller will allow you to set the fuel mixture where you want, something you can't do with CIS- lambda (K-Jet).
> Once your on carbs you use the wideband as just a gauge to tune the carbs.
> The innovate MTX-L is both the gauge and controller in one. So you just need to find a place to mount the gauge. The wiring isn't that complex to setup, easier to install. You'll need power, ground, switched power, a 3/8" hole in firewall for wires to pass through. Send me a PM about the wiring details.
> For what its worth - a properly tuned 8v on CIS should be able to make in the range of 110-120 hp, with just bolt ons and a good tune. I believe this is part of that good tune.
> Cheers



sweet! thanks for the info. if i'm understanding correctly, the wideband will replace the current lambda sensor...does the wideband have the wire to hook into the oxygen sensor control unit like the old lambda has? certainly it must right? because you're making changes on the laptop so the engine performs differently.

last question...would you say it's worth it to get a wideband if i'm switching to carbs? if all i'm doing is reading the A/F ratio, can't a narrowband gauge on the old lambda do the same thing and save me some money? i understand that the widebanda is a much finer tuning and readout of the o2s sensor, but is it necessary?


----------



## ny_fam (Apr 3, 2004)

Yes the wideband controller replaces the O2 sensor of the CIS setup, and plugs into the CIS system via the O2 connector of the K-jet computer.
The controller doesn't come with any of these connectors you'll need to make a wire harness or buy one.

Is it worth it, I think its a very worth while mod but you have to decide if its worth while for the time you'll be using CIS.


----------



## redpig (Mar 29, 2004)

any literature on how it wires up


----------



## ny_fam (Apr 3, 2004)

Follow the innovate link at the top of the thread or send me a PM for details.


----------



## booested4door (Jun 10, 2004)

*FV-QR*

this is bad a**! the innovate link up top stopped working though. id love to read it.. def. thinkin this is a must do. notice better gas mileage?


----------



## ny_fam (Apr 3, 2004)

We'll be making a the wiring harness to make this work. I may have the content from that link stored away here, We'll see if we can get some version of it back online. The Innovate forum may just be updating etc..


----------



## booested4door (Jun 10, 2004)

*FV-QR*

really?! how much will that run and what will it entail? please dig this info up man!!! ill prob. be doing this as soon as i get my rabbit back......need as much info as you have please


----------



## ny_fam (Apr 3, 2004)

PM sent.


----------



## mr sarcastic (Nov 2, 2006)

The link to the innovate write up is dead! I'd really like to do this, anyone got a write up for it? I have my wideband and I'm ready to make it happen.


----------



## Hummdog (Nov 23, 2009)

Im looking to do the same if there is an updated link, or anything similar out there.


----------



## noizze (Aug 19, 2003)

I've been using the LC-1 in my cabby for about 4 years now. The ability to tweak the Lambda switch point and adjusting the transfer rate is what makes it all worthwhile for me.:heart: For those of you who are try to race an old CIS car, one of these will help you make more power.


----------



## Mark0ne (May 19, 2012)

Sorry if this is a stupid question. So the tuning capabilities wouldn't work on a cis basic car... Right?


----------



## nbvwfan (Aug 15, 2007)

Basic with out Lambda, it would not work, though on a pure basic setup, you could manipulate the heating strip in the WUR. 
From what I gather in this someone is writing about sending a signal to manipulate the frequency valve duty cycle (lambda valve), in order to regulate upper to lower fuel cahmber pressure. In theory it will work, applicationally, it will take a lot of trial and error, especially if you are dealing with a boosted application.
I know because I am, although I am doing it to a CIS-E platform (K-Jetronic), with the DPR, taking the Lambda's place and enhancing it with faster and finer response. 
Though applicationally, my setup is a crude hodgepodge of a Hobb switch and playing with a fixed signal to effect the DPR (future plans are a MAP and TPS). All this while using my wideband as a "window" into the running conditions so I don't melt pistons.


----------



## ps2375 (Aug 13, 2003)

CIS does a good job of holding the AFR that you set it to. The WB is a good way to see where the AFR is at and then adjust it. Unless you get close to the systems limits, a good functioning CIS is hard to beat for what it is.

When we swapped the 16V into the Scirocco (which had CIS-Lambda), that is what we did, as trying to feed the lambda controller the signal from the WB did nothing but make it go lean, no matter how we programmed the WB. We just disconnected the frequency valve's power and set the mixture with the 3mm allen and had solid AFR's from idle to redline.


----------



## nbvwfan (Aug 15, 2007)

That is because a signal to the lambda causes a lean duty cycle, as in IIRC, opening lower chamber flow, increasing the lower chamber pressure and restricting the flow that is allowed to be metered out the upper chamber ports. 
Did you try switching the voltage?
That is what I am doing on the DPR, but in that the DPR is a magnetic coil that can accept positive and negative current, the lambda cannot as it is a valve that is switched on.


----------



## ps2375 (Aug 13, 2003)

We had the WB set up to output a NB signal in place of the NB O2 sensor. And yes, once the Frequency valve was unplugged, the system goes lean, then you just adjust the mixture screw to set the mixture(AFR) and that is pretty much where it stayed. We did have the WUR mounted up where the battery used to be, so as not to change the system pressure and therefore the the mixture.

The Lambda system has a controller (under the dash) along with the NB sensor along with the Frequency Valve on the Fuel Distributor.


----------



## teknikALLEN (Jul 14, 2010)

*FV-QR*

http://www.innovatemotorsports.com/products/MTS.php


----------



## Shavarsh (Jan 12, 2014)

So the consensus is that these gauges are a more useful tool than dwell tuning? For setting a basic tune/diagnostic work is there a large advantage to the gauge? Thanks in advance, I am trying to justify buying the whole wideband setup when I could just buy a dwell meter. Thanks


----------



## ny_fam (Apr 3, 2004)

Dwell meter can get you close to a good tune if you have a dyno or wide band read out. Other wide the dwell readings will get you factory AFR . Remember normal CIS -k jet (GTI) injection runs open look (not computer controlled) at wide open throttle not real fuel metering other than your basic dwell settings. With the wide band controller you are running closed loop all the time. (computer controlled all the time) The computer controls fairly accurately your AFR for WOT and non Wot driving.


----------



## leecatd8209 (Jul 13, 2010)

Does anyone have a good write up, or link to one on how to do all this? Or know if Scientific Rabbit still sells the harness kit for it? I'm building a CIS turbo frankenturd, and this would be perfect.


----------



## Hoffa (Jun 7, 2001)

Wow I like this thread and found it while researching WB's. NY you have a PM.
Hoffa


----------



## mojavemesa (Sep 4, 2015)

This is the guts of the cis lambda controller. https://youtu.be/aE_tfbQPPqo
As you can see the problem is the cis lambda controller is slow to react, I assume this is on purpose so it doesn't overshoot the mixture requirements. Because of the reaction time simply switching o2 signals may not be the best solution especially for quick on/off throttle situations. How about feeding both o2 signals to the two separate cis lambda controllers and just switching the input of the frequency valve between the two cis lambda controllers outputs using the wot switch? I forsee no lag this way and would cost only another cis lambda controller box


----------



## TheRealEddie (May 8, 2006)

Yeah, I had a friend who used the MTX-L out for CIS-E (KE Jetronic) and it didn't work all that well under WOT for reasons described above. We went a different path for CIS-E which I posted. Similar idea in terms of using an MTX-L but different in that we added some of our own electronics in there to control the DPR. I didn't think to see how to do that with plain CIS which might be simpler? 

-e


----------



## epic designs (Feb 4, 2004)

TheRealEddie said:


> Yeah, I had a friend who used the MTX-L out for CIS-E (KE Jetronic) and it didn't work all that well under WOT for reasons described above. We went a different path for CIS-E which I posted. Similar idea in terms of using an MTX-L but different in that we added some of our own electronics in there to control the DPR. I didn't think to see how to do that with plain CIS which might be simpler?
> 
> -e


Do you have any ideas for implementation on CIS-basic, with no frequency valve?


----------



## Butcher (Jan 31, 2001)

CIS basic does not have any way to control the fuel delivery with electronics. The only electronics is the heater in the warm up regulator, cold start valve, and the fuel pump.

What are you trying to do?


----------



## DbilasTDI (Nov 5, 2017)

hook a digital DC volt meter to the O2 sensor fat output wire. Adjust mixture for .75-.80 VDC at idle. 
reading will flutuate, center it around the .75-.80 V. Done


----------



## Butcher (Jan 31, 2001)

But CIS basic does not have an O2 sensor. If you put an O2 sensor in the exhaust, adjusting it to that value does not really set the mixture right.

Read how a narrow band O2 sensor works and you will see, it only helps in a really narrow band. Certainly not good enough to adjust a fuel mixture.
http://www.enginebasics.com/EFI Tuning/AF Ratio Basics.html


----------



## DbilasTDI (Nov 5, 2017)

CIS Basic you do by ear. Some thing with CIS Lambda with a big cam, Throw out the numbers and go with what runs best.


----------



## Peter Tong (Jun 17, 1999)

wow... i haven't been back to vortex in a while so its kind of interesting seeing this CIS section.

My Lysholm supercharged Cabriolet has been in storage for years as well so i haven't played with CIS in a while and frankly am a bit rusty lol. Someday i'll get the new 2.0 8v with 42/35mm solid lifter valves in and have at it again.

When i was dyno tuning my Volvo 240 turbo CIS setup on it... i found i could not get the fuel i needed using the Volvo warm up regulator. i ended up adding an additional fuel circuit to directly drain control pressure with a frequency valve controlled by my VSAM setup. VSAM had load and duty cycle map which could be accessed using a laptop and the special software. Normally this fuel circuit would be closed, but under boost would open according to the duty cycle lookup point on the map.

i did a lot of injector testing... and was able to get top end fuel flow up to 420 cc per injector (per minute?). i think it was close to 100% more than the stockers.

i also found that after doing this that my new Bosch fuel pump was not supplying enough fuel at the top end... things were going lean. Ended up having to add a Boost-A-Pump to fix that problem (this was triggered only under boost).

The car ran perfectly well with CIS and the charger (and old video):

https://www.youtube.com/watch?v=J6EBPYnS_Qw

i ended up tuning things under boost to run around 12:1 afr... and of course off boost with the stock lambda valve in control dithering around 14.7 (all measured with a wide band).

Anyways just my $.02 now that i am back visiting the vortex.


----------



## Glennbon (Aug 13, 2018)

*ABA/CIS timing*

I’ve built a aba with cis basic top end and runs good. I welded in a 02 bung and tuned with a wide band which helped. 
What should be the max timing and at what rpm? Engines in a 82 Westy


----------



## ny_fam (Apr 3, 2004)

Depending on compression ratio, they will make best power around 28 total degrees advanced for below 10:1 CR.

With the lower compression engines its possible to have more ignition advance than required to make the most power, and even to the point of loosing power, before signs of detonation.

Its also important to look at the specs for the distributor you have to see when the advance comes in and at the max is.
ny_fam


----------



## Glennbon (Aug 13, 2018)

The compression spec for the ABA is 10:1. I used a mls head gasket with two extra .009” outer shims so I’m thinking I’ve lowered it maybe a point. I have to use Chevron 94 octane to avoid detonation which I don’t mind as it’s a seasonal vehicle. 
But when I checked with the timing light the full advance was 40* @ over 3000 rpm. 
It’s just a stock 1.8 cis distributor. I guess I’ll try and recurve it with lighter springs and limit the advance


----------

