# Please help!!!! CIS fuel issue, Im desperate!!!!! PLEASE!



## btsclan (Sep 2, 2011)

I really need some help, Ive owned my 85 gti for not even a week and Ive only driven it twice.

The car will start and idle but then die when I give it gas, WTF!!! Ive replaced nearly all of the vacum lines, replaced plugs/cap/rotor, new fuel filter, and double checked everything.....this is what happens, I start the car, it idles fine for 5 seconds, then slowly gets worse and dies, BUT if I hit the gas anytime during the idle it boggs down and dies.

So the CIS fuel flapper, I can keep the engine running by manually moving the flapper with my hand and at the same time adjusting the throttle body.

What is going on? Do I need a new CIS flapper?? This is driving me nuts, 

Please please if you have ANY idea what is going on please let me know, I really dont want to tow this car to a shop and pay out my a$$ for labor, Ive been wrenching on cars my whole life but this is my frist VW.


Please a new VW owner out!!!!


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## DubLuv1 (Oct 6, 2007)

Bump for same problem.

Ive heard that you need to clean your pressure valve. From what ive heard, this is a common problem, because it can get gunked up and get stuck open/closed. If you do it, let me know how it works out. Im doing mine Sunday

pic from another thread:


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## btsclan (Sep 2, 2011)

I will give that a try tonight and let you know if it works.

thanks


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## armymech666 (Sep 29, 2007)

have you replaced your injector seals?


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## ziddey (Apr 16, 2006)

check the accordion boot by the throttle body, and the one above the fuel distributor for cracks. also make sure they're clamped on properly. if you can maintain idle by playing with the air plate and throttle body, then good.

build a dpr test harness and see what it does.

check that the mesh filter has been removed from your inlet hose at the fuel distributor.

does it stay running if you unplug the coolant temp sensor (the white plug on the underside of the coolant flange on the head)


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## scirocco8v1984 (Oct 18, 2006)

*?*

frequency valve buzzing? jump the frequency realay and check connector to valve with test light ,,,should give a lead!


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## dkfackler (Feb 8, 2010)

You _really_ need to test fuel pressure/delivery. This sounds like a plugged control pressure regulator to me. It causes excessively high fuel pressure and leans the mixture so far that the engine won't run. 

Don't mess with the pressure valve in the fuel distributor until you've established that the pressure is wrong, and the control pressure regulator isn't the culprit.


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## ziddey (Apr 16, 2006)

85 gti has cis-e


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## MacGruber (Aug 20, 2010)

I can't help on the CIS-E part, but I do know the airbox has wiring and vacuum hoses to check.

Check the idle screw, it may even be missing. The seal could very well be 27 years old. 
Could adjust it for a very high idle speed. Passages could just be crudded up. 

Another trick is to adjust the throttle cable for a very high idle. Temporarily.

If it was just CIS I would say it has to be a vacuum leak since it runs if you move the airflap.


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## michaelnahodil (Apr 27, 2010)

dkfackler said:


> You _really_ need to test fuel pressure/delivery. This sounds like a plugged control pressure regulator to me. It causes excessively high fuel pressure and leans the mixture so far that the engine won't run.
> 
> Don't mess with the pressure valve in the fuel distributor until you've established that the pressure is wrong, and the control pressure regulator isn't the culprit.


^agreed^ I had the same problem a few years back (when i was CIS illiterate) and it ended up being the fuel pump. it was pushing enough pressure up to let the car idle, but was delivering nearly enough when a load was put on the motor. go to autozone, rent the fuel pressure tester kit, and check standing pressure (just turning the key to the on position). I'll bet you dont have near what it calls for in the bentley


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