Idle Valve stabilser clean or replace?

[flubber]

Hi I have a gti 89 digifant 5 door and revs are erratic on idle. Been told ISV might need cleaning or a further valve by manifold which cuts in if main 'warm up' is not working.
Done everything else...Mystery
cheers
Dave

[Leon R]

Definately try to clean it first. You have an 8v right? I think a replacement new is £140.
Tin of brakecleaner/carb cleaner is about £3-5.
Get two, remove the ISV and spray the parts where the vac pipes went into. If the residue is black, keep spraying, swishing it about etc until the residue is clear. Give it about 1/2 hour to dry (brake cleaner evaporates, the one we use at work does anyway!) or use compressed air to force out and remains and give that a go.

Even better would be to donor a working one tho.

[Conker]

Hi Flubber,

This is a common issue with Mk2's, so don't let it get you down. Some other things that have worked for other people:

 - Thorough clean of intake system
 - Remove and clean the idle screw
 - Replace the ISV control module located behind the ashtray in the centre console
 - Repair throttle idle switch
 - Air leaks
 - Adjust throttle cable
 - Setup your timing (I think there is a digifant tuning on here somewhere

Have a search through the forums on the above as a good starter for ten. Hopefully they are relevant to digifant, as I only know (very little) about 16v'ers.

Good Luck!

[8vreturn]

Definitly check for air leaks - I have just changed my rocker cover of my '88 pb for one off a mk3 8v and in all the excitement forgot to fully tighten either end of the rubber induction pipe.  I was on the verge of swapping everything back over when I realised that I didn't remember doing up the two clamps.  Problem solved.  With a previous golf I had problems with this pipe splitting underneath.