# Cis-e 1987 jetta wont idle or rev



## MMMataIV (Aug 1, 2020)

I bought an 87 Jetta gli with cis-e fuel injection system. I wanted a project car to learn how to work on cars. Despite my lack of knowledge I still bought the car even though it doesn't idle. but I'm determined. anyways when I bought the car I could step on the gas and keep the engine running until it was warm and then it would idle. so on a cold start the engine won't rev. I decided to replace the fuel distributor and differential pressure regulator to see if anything would happen, but no. however after doing that I noticed I could no longer rev the engine anymore. instead now when I step on the gas it kills the car automatically. 

So I went gun-ho and replaced everything from the fuel pump all the way to the injectors. so a new
Fuel pump
filter
accumulator
fuel reservoir housing 
pressure regulator 
fuel distributor 
differential pressure regulator 
injectors
idle air stabilizer
cold start injector
thermo time switch and
coolant temperature switch

still nothing 

then for some reason I decided to check the spark plugs and noticed that they were carbon deposits on them and they smelled like fuel. so I cleaned them lightly, again nothing. then I decided to replace the spark plug wires. after that the car would idle but its super rough. but it takes a couple tries to get it to actually idle. 

I need to check for vacuum leaks but its hard cause it won't idle, and when I bought it the guy initially said it was a fuel issue which is why I went all in with the fuel system replacements. The only thing I really haven't done is check the fuel pressure and adjust the idle/fuel ratio, but I'm super green at dong this type of stuff. so I want to get it done but because of lack of knowledge I'm in a rut. Anyone know what could possibly be the problem. I mean I only coming to the forums because it seems like the best place to go to for help. Would appreciate any suggestions.


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## Butcher (Jan 31, 2001)

First thing I would recommend is to stop replacing parts because you think they are bad. This rarely ever works but seems to be the first tactic people use. 

All the air must be metered so the fuel system can deliver the right amount. Smoke testing the intake system is the best/only way to know if you have any air leaks. Most people do not have a tester but it's worth the money if you are a pro. It's worth your money to find someone that can do that on your engine. 

By changing the fuel distributor, usually you have to tweak the CO screw to set it up correctly. 

Ignition timing needs to be checked and adjusted to specs.


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## DbilasTDI (Nov 5, 2017)

do you have fresh premium gas?


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## garryt (Dec 22, 2016)

blowing cigarette smoke through a vacuum line is very effective when looking for leaks:laugh:


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## garryt (Dec 22, 2016)

garryt said:


> blowing cigarette smoke through a vacuum line is very effective when looking for leaks:laugh:


disclaimer- of course I don't encourage smoking!


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## MacGruber (Aug 20, 2010)

Cis-E Idle is set by the ISV. I hear they need to be cleaned. My CIS car is different.
Have you checked the Throttle Idle Screw? The little O-ring seal on it (6mm ID x 2mm) gets hard especially Viton seal after 10 -20 -30 years.


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## 91JET16V (Jan 6, 2012)

I would say check all those cloth covered rubber hoses VW likes to use. Last time I messed with adjusting my fuel distributor I used an Air/Fuel meter reading my exhaust to achieve the correct ratio. But, like somebody brought up, if you haven't checked timing, it could be that as well.


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