Misfire, Engine Goes To Restart When Turned Off & Low Idle - All Intermittent

Hi,

Firstly hello from Nova Scotia Canada!

I am hoping someone on here may be able to give me some advice as to what is causing the issues I am having with my '87 Cabriolet.

It's a 1.8 Injection Auto (I know auto's are awful but car's rust out here so you have to take what you can get) and I am getting to the end of my rag trying to find the source of my running issues.

So far I have changed the injector seals, the fuel filler neck, cleaned out the fuel tank, set the timing up, cleaned out the air box etc and changed the spark plugs plus I have run Sea Foam through the petrol and the air box..

When the car runs properly it is near perfect, quiet, smooth and on all four cylinders.

However I am having multiple intermittent problems, which since I changed the spark plugs seem only to be affecting the car when it has warmed up.

These are:

Low Idle - not all the time, generally once I have pulled away a couple of times it will act normally (800rpm in drive and just under 1000rpm in park with minimal hunting) and it is fine starting from cold, choke kicks in and drops revs down once warmed up.

Stuttering off the line - this gets worse the more I use the car, I can drive short distances without this happening but as soon as the car is warm it will do it, sometimes with more persistence than others. It feels as though it is running on three cylinders as the car is really down on power sometimes to the point where I am barely moving, until it kicks in and you shoot off down the road.

Restart after switching the engine off - This happens less regularly but I would say that it does happen at least once if the car is used for any extended period of time.

Just to re-iterate I have sorted the timing, changed the plugs, cleaned the fuel system and replaced the injectors and the car runs perfectly once I am away from the line and going down the road.

I was really hoping there may be something electrical that would cause the issue?

Any ides would be greatly appreciated as the VW specialist in the area and another local mechanic have both attempted fixes which have not worked.

Thanks in advance!

ShabbyCabby



 

What injection system do you have fitted to the car, k-jet or digifant?
If you are not sure post up picture of your engine.
Did you replace the HT leads, dissy cap and rotor arm?