# How to trick CIS-Lambda FV into longer duty cycle?



## dogzila22 (Apr 1, 2008)

How to trick CIS-Lambda FV into longer duty cycle? or maybe better is convert cis-L to cis basic, what I need to do if so?


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## WaterWheels (Aug 14, 2005)

*Re: How to trick CIS-Lambda FV into longer duty cycle? (dogzila22)*

Before discussing just how to go about doing either, I have to ask why? CIS w/Lambda tries to maintain a correct mixture from idle up to when you really floor it (WOT)(full throttle). When you do that the full throttle switch signals to the control unit to disregards the O2 information. If you convert to CIS basic or alter the Lambda system you will use more fuel during idle and part throttle with no real benefit at full throttle. Many people have reasons for such a change, so as I said, just why would you want to?


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## dogzila22 (Apr 1, 2008)

*Re: How to trick CIS-Lambda FV into longer duty cycle? (WaterWheels)*

Because I changed exhaust manifold (toilet bowl) to less restrictive 4-2 exhaust manifold with dual pipe which hasn't O2 sensor. (maybe from passat very long dual pipe). I use engine at hillclimb


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## ny_fam (Apr 3, 2004)

*Re: How to trick CIS-Lambda FV into longer duty cycle? (dogzila22)*

Well if its a race car O2 is only used for tuning then, CIS L the O2 isn't used under WOT.
The ECU takes the O2 out of the picture and sets the duty cycle to 60 or 70%.
You can mess with the CPR to allow more fuel at the set duty cycle, or try and get a O2 installed and a lc-1 and run the O2 in closed loop.


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## dogzila22 (Apr 1, 2008)

*Re: How to trick CIS-Lambda FV into longer duty cycle? (ny_fam)*

what is lc-1? I am thinking about 16 valve warm up regulator.


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## ny_fam (Apr 3, 2004)

*Re: How to trick CIS-Lambda FV into longer duty cycle? (dogzila22)*

Take a look at dyiautotune.com
Its an innovate product. Programable more accurate wide band O2 controller.


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## A1peopleS2wagons (Dec 2, 2010)

dogzila22 said:


> Because I changed exhaust manifold (toilet bowl) to less restrictive 4-2 exhaust manifold with dual pipe which hasn't O2 sensor. (maybe from passat very long dual pipe). I use engine at hillclimb


Revived from the dead.
The 19-82 j/h has the 4 into 2 with a 0-2 sensor.


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## Glegor (Mar 31, 2008)

WaterWheels said:


> Before discussing just how to go about doing either, I have to ask why? CIS w/Lambda tries to maintain a correct mixture from idle up to when you really floor it (WOT)(full throttle). When you do that the full throttle switch signals to the control unit to disregards the O2 information. If you convert to CIS basic or alter the Lambda system you will use more fuel during idle and part throttle with no real benefit at full throttle. Many people have reasons for such a change, so as I said, just why would you want to?


my CIS-L doesnt have any idle or WOT switches?! (86 golf)


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## WaterWheels (Aug 14, 2005)

Glegor said:


> my CIS-L doesnt have any idle or WOT switches?! (86 golf)


And you quoted what I said back them because? By the way, some do and some don't (most I believe dont). So again, what's the connection here?


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