Guys some help if you can. Gave my Mk2 a heart transplant. Everything is going ok except I had a high idle. Was waiting on a timing gun and taught it would sort it. Long story short, corrected timing but the idle is still high. Any ideas? Adjusted the little grub screw on the throttle arm, but not sorting it. Any help would be mega.

Dexmr2 wrote:
Guys some help if you can. Gave my Mk2 a heart transplant. Everything is going ok except I had a high idle. Was waiting on a timing gun and taught it would sort it. Long story short, corrected timing but the idle is still high. Any ideas? Adjusted the little grub screw on the throttle arm, but not sorting it. Any help would be mega.


Dis u try cleaning out the throttle bodies and idle control valve?

Trottle position sensor?

i had a similar high idle issue before that was accompanied by a misfire. turned out to be the lambda sensor.

Can be a "vacuum" leak after the throttle body. Any rubber hoses you see attached to the inlet manifold after the throttle body could be an issue. Pinch each one with a pair of pliers when the engine is running and see if that drops the revs.

Guys thanks for all the help. It's gonna be Sunday before I get my head under d bonnet. I'll keep ye posted.

Guys, thanks again for all your help. Well long story short, I swapped out my complete throttle body with my spare, including throttle position sensor and ICV, and same problem, so concluded it was something I did when repining the rev1 ECU to my rev2 loom. I had moved the RSO & RSC pins as per a schematic, but it showed the red & green wires reversed, so I did, but guess what, should have left well alone. Anyways, sorted except for a little vac leek on my turbo smart bump valve, just an oring and she's idling sweet at 800RPM...

Good job!

Good work! Mine idles at 800rpm but has an ever so slight jump in the rev counter needle thats driving me nuts!! Small vac leak im thinking! Thoughts?