Idle issue - Golf GTI

[Miha]

Hey all, I've recently bought a 2000 Golf GTI as a get-around car. Love driving it so far although I've noticed the RPM will fluctuate up and then back down about 50 RPM, does the same when Aircon is turned on. I tried removing the MAF sensor connector, still did the same thing and of course didn't produce any power while driving.

Other than that the car drives well, comes onto boost quite hard, power seems to teeter off at about 4,500RPM.. Hope this is normal?

If you guys have any ideas that would be great.

Thanks,

Miha.

[JustCruisn]

That hiccup in the idle is common on chipped cars. Has yours being chipped ?
Other causes are vacuum leaks.

[Miha]

I don't believe it's being chipped, it's pretty standard all over.

[Fizz]

I had/have this issue 2 replaced MAF disappeared for a while but came back last week Thursday with avengence 2 the point while idling it would stall and hesitate 2 start. Couldn't find any leaks/ anything unplugged. As out of the blue as it started it so 2 have disappeared. Vagcom didn't pick up anything either.

In most cases as advised it's MAF/ vac leak. But they do suffer from Gremlins every once in awhile

[Miha]

Thanks guys, I'll take the MAF out tomorrow and give it a clean... Plus recheck all the vaccum hoses. Hopefully that'll fix it after I do a reset also. If not, maybe I'll look for someone that's got a VAG-COM and wouldn't mind looking if it's bring up any errors before I purchase a cheap ebay item... That in it's self will give me problems I'm sure..

[Guest0608]

Hey all, I've recently bought a 2000 Golf GTI as a get-around car. Love driving it so far although I've noticed the RPM will fluctuate up and then back down about 50 RPM, does the same when Aircon is turned on. I tried removing the MAF sensor connector, still did the same thing and of course didn't produce any power while driving.

Other than that the car drives well, comes onto boost quite hard, power seems to teeter off at about 4,500RPM.. Hope this is normal?

If you guys have any ideas that would be great.

Thanks,

Miha.

Could be your throttle body needs a clean out, I had a GTI turbo in the uk and found a boost and poor idle fault, took me ages but worked it out to be the throttler body, removed the whole throttle housing and cleaned out with a clean lint free cloth and some brake fluid, didnt look that bad, just had a thin film of oil on it, refitted and re-adapted to the engine ecu, and never faulted again............VW......

[McDub]

i'd clean the throttle body before cleaning the MAF. the MAF is delicate so i wouldn't touch it unless you know it's the fault...

[Miha]

i'd clean the throttle body before cleaning the MAF. the MAF is delicate so i wouldn't touch it unless you know it's the fault...

Thanks, I'll give that a look first!

[geoff_gti]

Was going to suggest the throttle body as well, since I've had that cleaned on mine. Just make sure if you do it yourself, that you run through the realignment process with VAGCOM once you connect everything back up.

http://www.ross-tech.com/vag-com/cars/vwmkIV.html

[Jmac]

Yeah clean it and re adapt, 1st ive heard of the idle hiccup after a chip????
The throttle body is prone to gumming up and it upsets the base idle. Please open the butterfly with the throttle mech, and dont just push it open on its own, this will stuff up the potentiometer in the throttle body, went to the aid of someone lately who did jjst that and killed the throttle body
Best to know before hand
Cheers
Jmac

[Fizz]

Thanks JMAC will clean mine this weekend as well. As I did notice it was filthy when i removed it to get to the intake manifold 2 do the thermal intake gasket and replace the thermostat.

[Guest0608]

Yeah clean it and re adapt, 1st ive heard of the idle hiccup after a chip????
The throttle body is prone to gumming up and it upsets the base idle. Please open the butterfly with the throttle mech, and dont just push it open on its own, this will stuff up the potentiometer in the throttle body, went to the aid of someone lately who did jjst that and killed the throttle body
Best to know before hand
Cheers
Jmac

Good advice about opening with the cable mech Jmac, thats just the early ones tho, later models like mine had were flybywire type, just open with care and what ever you use to clean it with be gentle, as Ive stuffed one up myself after a clean and they dont come much under 1k for a genuine throttle body! .............VW.............

[Miha]

Yeah clean it and re adapt, 1st ive heard of the idle hiccup after a chip????
The throttle body is prone to gumming up and it upsets the base idle. Please open the butterfly with the throttle mech, and dont just push it open on its own, this will stuff up the potentiometer in the throttle body, went to the aid of someone lately who did jjst that and killed the throttle body
Best to know before hand
Cheers
Jmac

Well today I cleaned the Throttle body succesfully, behind the butterfly was a bit of of black oily/greasy stuff... I disconnected the battery before doing the clean and then reconnected it after, there was some high pitched buzzing noise coming from the throttle body after I turned on the ignition..It lasted about 30 seconds or so. I hope this was the calibration..

After all this, the car does run smoother, but unfortunately still the same idleing problem. Maybe this was the lack of vag-com realignment. I'll take a video later just to demo' it.

[h100vw]

The throttle body will adapt every time you turn the ignition on if you don't start the engine.

The buzzing is normal. Are you sure there's no air leaks on the inlet?

Gavin

[Miha]

As I mentioned earlier here's the video.

http://www.youtube.com/watch?v=6qyEuMqA62Y

Thanks for all your help guys, I really appreciate it.

Miha.