hunting idle when cold

[Gouldy]

hi guys, my recently acquired, Coupe GT has got a hunting idle when cold

when warm it idles perfectly, and the car drives perfectly when hot and cold

I have check the idle stabiliser for Current going into the unit and there is power going to it, however if i unplug the unit (whilst its hunting) nothing changes.

is this a sign of a nackered idle unit or does this unit only work at certain times

the car is also running quite rich

many thanks

jim

[Isimmo]

Originally Posted by Gouldy

hi guys, my recently acquired, Coupe GT has got a hunting idle when cold

when warm it idles perfectly, and the car drives perfectly when hot and cold

I have check the idle stabiliser for Current going into the unit and there is power going to it, however if i unplug the unit (whilst its hunting) nothing changes.

is this a sign of a nackered idle unit or does this unit only work at certain times

the car is also running quite rich

many thanks

jim

Hmmm... Try disconnecting the cold start injector....

[Gouldy]

i take it this is the one with the green plug on the IM? should i disconnect it when running/hot/cold?

[Isimmo]

Originally Posted by Gouldy

i take it this is the one with the green plug on the IM? should i disconnect it when running/hot/cold?

Yes, the cold start injector is up on the inlet manifold, we run both of ours disconnected all year, they're ideal for very cold starting, but with the uk's temperate climate they can, even when working normally, flood the engine when cold. If the injector is partially blocked and firing longer than required, it could make the old girl hunt. BUT, it could quite easily be something else.

[BIGGYIN]

Anyway of over hauling the cold start injector?So expensive,for what they are.

[Gouldy]

thanks for your help isimmo, much appreciated, will keep you updated!

[Phil Payne]

Originally Posted by Isimmo

Yes, the cold start injector is up on the inlet manifold, we run both of ours disconnected all year, they're ideal for very cold starting, but with the uk's temperate climate they can, even when working normally, flood the engine when cold.

Bolleaux.

There's something wrong with your systems - probably they've been set over-rich to start because something in the cold start system is bust. The idea that Audi would ship hundreds of thousands of cars with cold start valves fitted that they don't need is ludicrous. They do hot start tests in Death Valley, for heavens' sake.

I hate to think what your fuel consumption is.

[Gouldy]

i tried the 6th injector this morning . And no difference i am afraid.

[Isimmo]

Okay-doakes, back to stage one then...

[Tarka]

Does this engine have an idle stablisation valve? Common problem on 1.8 Golf GTI engines. The ISV can get dirty and cause this hunting. ISVs can be cleaned but not too expensive to replace and quite an easy job.