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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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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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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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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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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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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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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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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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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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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...:p
 

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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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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?



Mines going towards a turbo CIS build.
 

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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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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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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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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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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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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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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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