I've just got my 1990 8 valve GTI up and running after being stood for a while, but it running rough and i'd appreciate some suggestions as to what it could be. Its coughs and splutters on light acceleration, but runs find on wide open throttle. Idles fine. The oil temperature is a bit high - its running between 110 & 120 degrees, although coolant temperature seems normal (just below middle) The fuel gauge is intermittently working. (could be voltage stabiliser on the back of the clocks?) I've recently replaced the in-tank fuel pump and changed the oil. Spark plugs are a bit sooty, but not too bad. Could it be knackered main fuel pump? Air meter? Thanks
The very best thing you can do is to follow rubjonny Digifant tuning guide: https://www.clubgti.com/forums/inde...ose-and-tune-your-mk2-digifant-gti-8v.124949/
It sounds like it's running lean possibly. On WOT the digi goes quite rich. Are the plugs very white ? A struggling pump could well caught to be a bit lean too Was the afm spring ever adjusted ?
Mine ran like that when the FPR was shot. It was easy to see as fuel ran down the vacuum to the clear pipe on the air box. It might not be that, but it could be a fuel pressure issue.
Thanks for the info. Lean running sounds like it makes sense. I’m planning to get it on a gas analyser and timing gun later in the week - so will make sure it’s set up properly. I just went out to see if I could adjust the CO screw a bit, but couldn’t see it in the hole . If it’s missing that would explain it!
Managed to get it out using a spline bit hammered in. The seal in knackered. Anyone know if you can buy the bolt/adjuster new? Also what would be a good starting setting when I put it back in (didn’t note the number of turns)
