Golf Gti Mk2 PB Engine Code Idling Far Too High....HELP PLEASE!!!!!

[TwistedAspect]

Hi there,

I have an 89 Golf Gti MK2 on a PB engine code and the thing is driving me to distraction.

I am fast running out of ideas, the car seems to want to idle between 2000 and 3000 rpm which I know is far too high. I have recently replaced the ISV but I do suspect that there is far too much air getting into the throttle body. I have trimmed back the throttle adjusting screw but it will not go back any further.

If I squeeze one of the pipes from the ISV, the revs drop back to between 900 and 1000 RPM, likewise if I disconnect the ISV while the engine is running, she again drops back to where she should be.

Any help would be much appreciated!!

Jay

[dubslug]

im assuming u have checked for all the normal air leaks??
has this problem just started happening??
welcome by the way

rik

[Outlaw-Torn]

Try cleaning out the throttle body and airbox, they'll have loads of crap in them ( I know mine did!). Can you turn up the idle speed using the screw on the throttle body? If it's not having any effect at all, a new throttlebody is probably the answer, shouldn't be too much from a scrapyard. Also worth checking the ISV buzzez and vibrates slightly when the engine's running, if it doesn't it might be knackered. Is it a new ISV? Hope any of this helps mate...

[TwistedAspect]

Yes, this problem actually happened over night. The ISV seems fine as it does vibrate when the engine is on.

I will try cleaning out the throttle body and air box, see if that makes a difference, other than that is the air flow meter another reason it could be idling so high? I have tried playing with the lead connected to it and believe there is a loose connection there. When the lead is shaken, the RPM's seem to fluctuate really badly.

By the way, Thanks Rik....its about time I got some help with her )

[rubjonny]

If it still runs with the ISV disconnected then there is far too much air getting through the throttle body, it should stall!
It sounds to me like the idle switch is adjusted to far and is holding the throttle body open, its located underneath the throttle body and is only accessible if you take the inlet boot off.  Loosen the screws holding it on, and adjust it so that it *just* clicks when the throttle is closed.

After that you'l;l want to replace the blue temp sender with a new one from VW (not a pattern part they're rubbish) then check the idle & CO as per the FAQ in the maintenance & info section

[TwistedAspect]

Thanks...I will try all of the above at the weekend and let you all know how I got on

[dubslug]

if in doubt rubjonny is our local mechanic, were still trying to find something on th mk2 he doesnt know lol, hope u get it sorted

[TwistedAspect]

Checked the idle switch as per Rubjonny's suggestion...all fine there.

Buying a new Temp Sender from Murrays this afternoon....hopefully that will sort it

Just had to fit a new radiator......the list just goes on

Jay

[Steve_B]

You don't mean Murrays in Hatfiled do you? Bought a blue temp sender from there and it packed up after a few months. Everything else I've got from there has been fine though.

[GTI EDITION (aka LTD)]

 If I recall ,the wires to the idle switch on the throttle body can sometimes break and that can cause excessive idle speeds