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Model specific boards => Golf mk2 => Topic started by: borax on 17 August 2014, 18:41

Title: Idle stuck at 3000 rpm
Post by: borax on 17 August 2014, 18:41
I have a j plate 8v gti pb engine. I initially had issues with the idle going from 800 to about 3000 all on its own. I have done loads of things to try and solve it.......... Full service, plugs rotor arm, air filter, leads dist cap, mk3 rocker gasket, new blue sensor, new throttle body and new blanking tubes, and new gasket, at some point is has had a new isv. Now when I connect it all up it sits around 3000rpm adjusting the idle screw makes no difference.
I have checked all the pipe work and as far as I can see there are no. Vacuum leaks.

I currently have the isv feed to the throttle body blanked off and it runs/idles ok ish but I want to get it running spot on, anyone any ideas?
Title: Re: Idle stuck at 3000 rpm
Post by: Sgt_Lemon on 17 August 2014, 22:24
Does the fuel pump prime then switch off?
Title: Re: Idle stuck at 3000 rpm
Post by: borax on 18 August 2014, 07:42
I'm assuming fuel pump is ok, it runs ok with isv disconnected. How do I test fuel pump?.

Also, re problem, I have checked continuity between throttle switch, isv and ecu and it is fine
Title: Re: Idle stuck at 3000 rpm
Post by: Sgt_Lemon on 18 August 2014, 10:25
I was thinking to test the ecu.
Title: Re: Idle stuck at 3000 rpm
Post by: borax on 18 August 2014, 11:51
I will check. Im assuming you mean that if the pump doesn't stop priming there is an issue with the ECU. When checking this am i correct to assume that i need to listen to the fuel pump with the ignition on, then it goes quiet after a few seconds?
Title: Re: Idle stuck at 3000 rpm
Post by: Sgt_Lemon on 18 August 2014, 13:00
That's the one, if the pump doesn't turn off again the the ecu is shagged. If not then it's a nothing thing to tick off the list.
Title: Re: Idle stuck at 3000 rpm
Post by: borax on 18 August 2014, 19:37
OK so the pump primes OK and then turns off OK, vacuum leak i have missed??
Title: Re: Idle stuck at 3000 rpm
Post by: Sgt_Lemon on 19 August 2014, 05:52
To me it sounds to erratic to be vacuum, what have club gti said? Try looking at the wires to the dizzy, maybe hall sender.
Title: Re: Idle stuck at 3000 rpm
Post by: Mr Blue on 23 August 2014, 21:13
Have a look at the rubber intake pipe that joins to the maf sensor. Usually the speedo cable rubs through and causes un-regulated air to enter the inlet.