Author Topic: Cannot reduce idling speed (Read 2623 times)

alpesh · « **on:** 03 October 2005, 12:55 »

Need some advice.........

Got a MK1 Gti convertible. Brought a home tune up kit. I adjusted the CO mixture but could not reduce the idling speed below 1100 revs. I can increase the idling speed but I want to drop it to around 950 revs. Whats the problem?

?

Tucker · « **Reply #1 on:** 03 October 2005, 21:50 »

could be an air leak on vacume hose or choke sticking.

cheers
Tucker

BobbyT · « **Reply #2 on:** 10 October 2005, 19:25 »

how would you know if the choke is sticking? also how do you go about sorting it out??

Tucker · « **Reply #3 on:** 10 October 2005, 19:51 »

take off the air filter, look in the carb and you will see the butterfly, should be closed when cold. start her up and let her warm up. should see the butterfly open as she does. you will see the choke on the side of the carb. will have some water pipes coming out of it if auto. a bit of lube should free her off but it might me the coil in the choke that has gone, metal spring the expands when warm

cheers
Tucker

Tucker · « **Reply #4 on:** 10 October 2005, 19:53 »

Doh...

Just noticed its a GTI

ignore the above

Tucker

alpesh · « **Reply #5 on:** 11 October 2005, 11:43 »

Cheers for the replies - yeah, i got abit confused when you started to talk about chokes.......

The car idles around 1100 revs - OK for now. Taken me over a year to get it on the road - so glad to be driving it.

Mk1Mad J - 16v · « **Reply #6 on:** 11 October 2005, 12:08 »

Have you checked your idle screw, i had a similar problem with one of mine and it turned out to be the o-ring which had gone hard so it was letting air in and not staying put. i'd adjust it and the revs would go straight back up again.

easy test for you - start the car let it settle then turn the screw out slowly a couple of turns, (i'd expect it to be stiff at first then there should be slight resistance) does it make any difference to the revs?

NO. you need a new idle screw - its a special order part (i may have the part no. indoors)

YES. your idle screw is ok

hope this helps

Tucker · « **Reply #7 on:** 11 October 2005, 19:02 »

Had the same prob on my MK2 gti.

The air box was sucking in to much air, was two vacuum type hoses that come out of the air box and go to the bit where the idle screw is (84 GTI), should be some sort of shim in there (air box end), mine was missing causing to suck to hard. only found this out on a rolling road tune

only 45 notes and you get the best from it

cheers
Tucker

BobbyT · « **Reply #8 on:** 11 October 2005, 20:54 »

cool, i will have a look!

richandhazel · « **Reply #9 on:** 13 October 2005, 15:07 »

As said above, you have a vaccuum leak (unmetered air entering). Could well be that idle screw, I've replaced that O ring before now. Also check all your pipes and in particular the 'Y' shaped contraption forward of the inlet manifold. Part of that can slide out..........took me bloody ages to find it when mine did that lol

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