mk2 gti 8v running issues

[rubberdubber]

Hi all

Bought myself a mk2 the other day!  I wanted a cheap everyday car to use for work and being a dub nut it had to be a mk2 golf GTI.  It has plenty of tax and mot but certainly isnt without its problems, but as to be expected for a £600 car with 150k on the clock!  Here it is:



Now for the problems!  It knocks and dosent move smoothly when reversing, suspect theres a broken tooth on the reverse gear, the sunroof is stuck, numerous water leaks,  but it has a running problem which is what i'd like abit of advise on.  it idles at 2000rpm, will dip to under 1000 every now and then but quickly rise to 2000rpm again    Any ideas?

cheers

[Jay]

Get the timing sorted with the help of Rubjohhny's guide:
http://www.golfgtiforum.co.uk/index.php?topic=33253.0

For leaks if you have damp foot wells:
http://www.golfgtiforum.co.uk/index.php?topic=70858.0

If you have crunchy gears peak here:
http://www.golfgtiforum.co.uk/index.php?topic=33100.0


 what do you mean by knocks when reversing? (you're not running an old lady over are ya?)  I suspect the getting the timing done will 'fix' your reversing problem.

[rubberdubber]

Thanks for those links Jay, i didnt realise you could adjust the fueling and idle on these injected engines, you learn something new every day!    I have saved all those links to my favourites, will certainly be giving it all ago

[OakeyDoak16v]

Good luck with those, hope you get the running problems sorted, shouldn't be too much hassle imo.

[fishnchipsx2]

I assume its a Digifant by the H-reg...

For the high idle, disconnect the Idle Stabilisation Valve (ISV) and clean it out with carb cleaner.  Do the same to the connecting pipes, and make sure it all gets put back together again tightly. Any splits in the pipes could cause the problem given also. 

Cleaning the ISV doesn't always work, but it certainly helped with mine.  Buying a new one is très expensive, so you probably don't want to go down that route... 

If you're not sure what the ISV is, give me a shout and I'll get my MS Paint skillz out... 

PS: unplugging the electrical connector on the side of the ISV should make the revs drop right down from 2000... you can run the car with it unplugged if its really bugging you, but it will idle really rough (or not at all) with a cold engine!

[OakeyDoak16v]

Recently had / having same problen tbh. Tried the same method but in the end found out that it was one of the senders that was faulty so cleaned it up aswell as thoroughly cleaning all the connecting breather pipes and touch wood so far it's been fine. The best thing i did tho was to properly clean out the throttle body with carb cleaner and that made a huge difference, would definately recommend doing that for starters.

[rubjonny]

check out the idle switch clicks when throttle shut, and make sure wiring connections round the back o the throttle body havent snapped

[rubberdubber]

Hi all

Thanks very much for the info, i like this forum alot!    Had a quick look during my lunch break today, when i pull the cylinder pcv valve thingy out the top of the rocker cover it idles normally, but when i put it back in the revs again rise to 2000rpm, the rubber grommet that holds the cylinder into the rocker cover is all spilt and nasty so if anybody has a spare please let me know!    The revs also drop when i disconnect the idle stabiliser valve, so ile give it all a clean and report back.