# CIS motronic w/ Wideband tuning discussion!



## redGTInj (Jul 6, 2003)

whats up everybody, havent been around these parts in a little hwile..but im back! got a 16v on motronic. couple of small goodies in tehre, a 50mm TT street cams some lightweight pullies.. all this run by motroinc with a GIAC chip. with an AEM wideband setup to overlook it all.

I was wondering what A/F ratios people are running at idle/part/wot? 
what chip?
what mods?
also if u can what milliamps do you have the dpr set at?

this could be a real informative thread, lets get this going!


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## redGTInj (Jul 6, 2003)

20 views no posts :sly:


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## so.cal.sparky (Nov 9, 2006)

I have a lc-1 that im controling the cis-e with i have it set for 13.5 to 14.1 and running 15% gas/ethenal mix(calforina gas mix)

runs great 
motor mods
eurosport header
2. in exhaust
tt fuel enrichment
decked head
tt cam gear
nuespeed wires
port matched
no a/c,ps
aba crank and alt


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## redGTInj (Jul 6, 2003)

very cool! sounds like a good setup.. whats up with the 2inch exhaust?? whats full throttle A/F look like?


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## so.cal.sparky (Nov 9, 2006)

Sorry 2 1/4 exhaust no res , 300 cell cat , I can't rember the muffler
Full open I'm at 14.1 .


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## redGTInj (Jul 6, 2003)

any plans for cams?


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## so.cal.sparky (Nov 9, 2006)

Yes haven't decided yet
After the new year I will be putting in a 9a ,lw flywheel,lw intermedite shaft,and swaping over to motoronic obd2

Looking for a good street cam and will be force fed also m45/62 is in the works


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## redGTInj (Jul 6, 2003)

sounds like a fun time! 

come on DIY CIS tuners!


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## nbvwfan (Aug 15, 2007)

I have an Innovate LC-1 setup in my build to see what is going on while manually tuning/building

Stock "RD" 1.8 8V 9:1 C/R
Supercharged with a G Lader on 78mm OEM pully (for now)
Running CIS-E (K-Jetronic), once again drawthrough setup
Homebrew RSR, full 2.5" custom tubing, stock OEM Intercooler
5 Cylinder Thick flange Euro fuel distributor
Bosal 4-2-1 Header
2.25" cat-less back exhaust
Corrado Intake Port matched
Stock GTI T/B
Dual BOV's boost recirculation
Have added Haltech F-5 fuel management to the CIS-E to control A/F under boost
DPR tuned to ~2mah, but this is just a relative baseline, and had tried many things with powertuning the DPR.

Aiming for 12.5:1 A/F under boost (10-12psi), then throwing in a 68mm pully to push the boost to ~14-16 psi

for history on this one of a kind build see:
http://forums.vwvortex.com/showthrea...-CIS-E-G-Lader


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## redGTInj (Jul 6, 2003)

very cool! ive seen u posting around..u seem to know ur stuff... im curious about why u dont run a traditonal fuel enrichment module as well... have u dynoed yet or anything to see what A/F's ur currently getting?


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## redGTInj (Jul 6, 2003)

:thumbupost pics, link didnt work


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## nbvwfan (Aug 15, 2007)

redGTInj said:


> very cool! ive seen u posting around..u seem to know ur stuff... im curious about why u dont run a traditonal fuel enrichment module as well... have u dynoed yet or anything to see what A/F's ur currently getting?


CIS-E already has the WOT fuel enricment switch and it did not effect A/F under boost.
Well actually, that is not entirely accurate. WOT did trigger the DPR to run current to the DPR but it's fuel enrichment was not linear, but rather an enrichment that was not very tuneable.
I did a lot of manipulating and DPR adjustment, yes, mechanical DPR adjustment, but the results were all about the same, and it usually ended up overfueling down as low as 10:1 even under boost.

A couple months ago I turned the corner on the prior setup and went about putting the fuel distributor in a blow "through setup" and relocate the T/B ahead of the meter to eliminate false air metering. My goal was to operate the fueling much like fixed displacement blowers were setup with the hope I could tune leaner under WOT and boost.
What I found was the Fuel distributor does not behave well in a blow through closed loop metering system. With many iterative changes and a general under-fueling trend and poor DPR adjust ability, I ditched the blow through and went back to a draw through setup.
As I have read in Supercharged by Corki Bell, and I am currently undertaking, some compromises are mandatory. One being that to run CIS witha G Lader, the fuel meter needs to be ahead of the charger and boost dump either needs to be plumbed back the the sensor plate better than the charger return on the OEM Corrado setup, or managed by the DPR current reversed with the idle switch. With the larger fuel meter (steeper cone and larger sensor plate) and the DPR set on the lean side, and the addition of the 5th injector to enrich under boost; I should have a better setup than the original arrangement that worked almost well enough.
My goal is to get a balanced A/F around Lambda under normal throttle and load situations but enriching to ~12:1 under boost and WOT.
If I have some issues I have enough new knowledge and old experience to tune it better.
If that does not work I can go back and also add a DPR signal triggered with a hobbs switch feeding a current to the DPR. But that is a last resort and one I did not find very acceptable from an economy, tuning, and MPG standpoint.

I fixed the link, read away and comment if you like. The feedback keeps me going and motivates me to stay clear of standalone.. this build at least..
When this works, I plan on doing it again on several other platforms, next up will be a 83 rabbit GTI, 1.8 8v, running CIS Basic and an Eaton M45.


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## redGTInj (Jul 6, 2003)

very good write up.. i am too VERY familiar with KE-jetronic.. u mightve read through my old posts form 07, 08.. i had and still have a mk2 16v... that made 181 WHP on CIS-E. obviously fully built bottom end, worked head giant cams etc...but MOST of the HP gained was with tuning of the fueling...

the stock WOT enrichment of CIS control unit, is not even enough for a stock engine.. i did have an adjustable potentiometer connected to my fuel enrichment module.. the stock DPR reading at WOT would shoot up to 14-16ma.. which was not nearly enough for my setup...TT and autoetch modules, would help bring ma values to aroyund 22-25ma..which was enough for most 16v's what i did find wa sthat, eleaving the dpr tuned a hir lean kept throtle respons crisp low and mid range...and i adjusted my pot so at WOT ma values would rear 35ma..that kept me rich enough for 8,300rpm.. and fuel mileage was virually untouched
something to look into..

i do like the different air cone setups, its intresting, there was a shop around here back in teh day that had a CIS g60, it was intresting to say the least..

i will check out ur threads for sure :thumbup:


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## nbvwfan (Aug 15, 2007)

I think I read up on your post with the POT and current driver setup for the DPR.
I tried that a couple months ago with a 5V circuit wired in to trigger the DPR. What I found was that the senor plate travel would max out due to the DPR losing its upper chamber pressure and under boost it would flutter.
When I had it draw through this did not happen but I did see the limitations of upper/lower chamber pressure and flow capacity being the hinderance to tuning.
Couple things I discovered, and you might also know.
The 2.0 16V fuel distributor has a longer plunger stroke. I don't have a cone and sensor plate, but I assume it was larger to suit this "euro" metering head plunger travel. I had one I tested for someone and I compared it to my 8v plunger and meter.
Comparitively, at full bore the 2.0 16V meter pushed ~800cc's in 3 minutes.
My "worked" 8V unit only pushed 650cc.

Another discovery after opening one up; each port is adjustable, but this is a factory calibrated adjustment and not intended for performance but more flow matching to stay within the 10% cc variance spec as per Bentley. My 8V meter had some issues with volumetric flow equivalence. At the onset of my tinkering it had a flow variance of ~20% (480cc-620cc @3 minutes). with about 30 flow test and some discrete adjustment of each port, I got the variance to under 4% and all to flow right around 625cc's in 3 minutes.
I imagine if I tried I could get it even better as well as increase total flow to at or near 700cc's.
I tried asking some of the "rebuilders" for some "tribal knowledge" on tuning and calibrating meters, but none would share any secrets, they would not even acknowledge or sell me spare parts, so I figured it out on my own, and bought what they would not source for me. (boo to  SpecialTauto.com )

In a future build I plan on testing the full potential of CIS with some worked 2.0 16V meters.
And doing a two stage, 8 injector, maybe dual charged or double G Lader setup.



If your are inclined to, you can mechanically adjust the DPR to respond to the electrical signal.
Since I had several as test subjects, I tried one out. With the microscrew fully seated, A/F was ~8:1 during the triggering , and backed out I was able to lean it out to 20:1.
Look up DPR power tuning in Google.
the black 2.0L 16V DPR is capable of even more.
And in my tests I also triggered as high as .5A, but being an electromagnetic valve, anything over 50 ma did not do more to the richening. This was also reversible, but lean triggering was more of a surprise discovery.


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## redGTInj (Jul 6, 2003)

intresting stuff!....im not following what the 5v wired in would do?
also keeping the dpr tuned at 2ma, is actually lowering pressure across the chambers...

u can try putting a 10k resistor from the coolant temp...making the "ecu" think its colder also keeping DPR ma values higher, keeping pressure higher..

id love to see this setup in person and on the dyno!


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## nbvwfan (Aug 15, 2007)

DPR readings are kind of the lost x-files of CIS.
While there are procedures for testing and adjusting the CIS manners, they all point to DPR current.
While looking into this I tested the voltage and found that the ECU sends positive and negative voltage, so 2 ma might be leaning and it might be richening.
Being a coil actuated between two flow ports, pulling it one way will lean it (negative current) and the other will richen it (positive current).
I probed this with a DVM was seeing the thermo-time circuit initiates about an 8v signal that then drops to 2v but will go up to about 5-6v based on the Lambda control regulating the DPR ma signal.
Ok, confused now? 
I tried wiring in a 3 bar MAP sensor that would run ~1.3v to ~5v depending on MAP (~2-15 ma). What I found was this triggered the DPR but non linear and would end up bottoming out the sensor plate travel and I will run out of fuel pressure. This also while the sensor plate was in stream with air flow and would cause it jump from atmospheric to + psi in pressure sweeps. This was frustrating and was found to be the biggest drawback to a blow through setup (Plate flutter). I tried wiring it to the CTS and found it was not able to be regulated. Actually, I tried a whole bunch of wired in resistors pot's, and signal circuits. What I found was the DPR would compete against them, or would overcompensate and not allow fine metering.
If the build was N/A and draw through the issues would be minimized.
In all, it has been a big learning experience, but one I am determined to sort out.


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## so.cal.sparky (Nov 9, 2006)

wow alot more than i ever wanted to know . Great info my learnings are from me trying to pass smog and get the best mpg/preformance out of the car.


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## vwpieces (Apr 20, 2002)

Haven't played with it for a while so I have forgotten most of the details of the tune. But after tweaking the DPR screw I achieved 12.5:1 AFR @ WOT. Never dyno'd it. 

16V 2.0L w/ 1.8 head, completely rebuilt, stock bottom end in a mk1 Jetta 
16V Scirocco 1.8 fuel system CIS-E 
TT enrichment 
9A trans (same as 16V 020) 0.80 5th 
Autotech cams, DIY P&P head & intake, matched, HD springs & LW lifters. Not my first P&P but I'm no expert. 
SI valves, undercut & swirl polished 
All aluminum pulleys, serp & no AC 
LW flywheel 
TT street header no cat, 2.25 TT w/ res & Borla 
Stock; airbox (uncut) intake tube & TB 
Oh yeah there is a scirocco 50mm intake on it now but I do think it ran better with the P&P original. 


No idea what the fuel economy is now but before the tweaks I was getting 30MPG highway with 0.89 5th; 32mpg highway w/ 0.80 5th & pretty much 28mpg mixed hwy/city. Much more fun now... definitely hungrier, but really not bad overall. 

Car is hibernating & won't see daylight till the salt is long gone. The '83 TD gets the dirty winter duties. 

Also have another head waiting... stage 3 P&P, Schrick 268/276, SuperTech valves inconnel exh. LW lifters HD springs, TI ret. Perhaps I'll update with more accurate info when that head is installed & the tune is fresh in my memory.


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## redGTInj (Jul 6, 2003)

very cool setup...i ran a setup like that for years!!


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