I suppose i should start wit the fact that the throttle is de-wedged but i dont think that is at fault.
When im driving if and the car is moving around it is fine. But if I accelarate, dip the clutch and let the revs drop they start bouncing from idle to just under 2000rpm in about a 1 second interval, so as you can Imagine its rather annoying when it trys to do it at every set of traffic light on the way home.
The only way i can stop it is to put it into first gear when stationary and lift the clutch to biting point and make the revs drop just under idle and then slowly depress the clutch pedal again once it has settled and then it will idle. Is it likley that i have a hole in a pipe somewhere that is sucking air in and confusing the sensors in the ecu and the potentiometer?
The next thing is the sticking throttle, I have read alot about the plates catching and not closing propperly and that a quick blip of the throttle can close it off once it has sprung back.
My problem seems different somehow, Bliping the throttle does sod all it just puts be back into bounce mode as i mentioned above. If the rev sticks it is usually at 2000rpm and the way i have to cure it is to again play with the clutch choke it down to around 900rpm and slowly release it so it sits at idle, if it were a sticking plate the revs would surely go back up to 2000rpm again after i depress the clutch pedal.
Its starting to really bug me. As evey one seems to think i want to race them at the lights because my engine is reving up all the time.
Can any one shed a bit of light on my situation.
Cheers
Gav
I think many a g40 has this problem,never realy got to the bottom of this both myself and jezza have had the same problem although most think its 51mm body related i swapped back to a standard body and it was ths same.
Usual things to checm that is recommended is:
Ignition timing and correct adjustment of idle
clean the isv
check for vacuum leaks
Change blue temp sensor
adjust co-pot on a gas analiser
check ecu goes into service mode if it does dont bother with blue temp sensor.
Check the throttle plate rest position screw
check idle and wot switch on throttle
check or replace throttle cable
these are all the things ive done hasnt cured mine although ot might help you,be intrested to see if anyone can genuinley answear this as i think its a VERY common problem.
Well i thought i nearly solved this last weekend. I replaced all the gaskets as i was gettin annoyed with it. Plus i did the boost mod again, and for a few days it didnt do it at all. I thought finally it has been sorted, but then a few days after it started doing it again. It has to be the idle screw or co pot i think.
lol this could be anything to be honest although my money is on some variety of air leak im guessing from the vacuum system although when i pulled a vac pipe of and left it open it didnt get any worse or start doing it when it wasnt doing it so maybe its not a vac leak.Need some old/experinced vw techs or mechanics to have some input.
i think its something we might just have to learn to live with :'( it is a major pain in the ass though if you drive your car regualarly on the street as it makes you look like a prize prick when parking !
Yeah i know what you mean. Other day i came to a junction and it started doing it, was a woman walking her dog that just turned and stared at me.
I dont think i have any vac leaks. If it hasnt got a jubilee clip on it then its usually vac silicone pipe that doesnt need it. This is an odd and stupid thing. Do you find on cold it gets stuck at 2k and then drops off after 5 secs or so?
I had the problem with the revs sticking at 2k for a while when cold, then dropping back down.
I solved this be setting up the ignition timing properly, then adjusting the idle screw. If you wind the screw out, listen to the idle carefully. You will hear it get faster and faster until it cycles ever so slightly. Wind it back in a quarter turn and it seems to run absolutely perfect.
May be worth a try as it cured my random super fast idle issue.
Cheers chris, will give it a go!
Jezza & Ant - deffo worth checking your idle speed settings, but can you also check whether it's better/worse if you stick some electrical loads on? E.g. heated rear window etc.
Ok andy i will give this a go tomorrow afternoon and see what happens. It would make sense if it was idle related. Remember when it just started doing it after we setup ready for mapping.
Ever get to the bottom of this?