Morning
So H15 is yet again being temperamental. Last night I drove from H-Dev (75 miles) faultlessly (excluding transmission). I stopped at the house to discover a 1200-1700rpm hunting idle. Being pitch black there was nothing I could look at.
This morning on cold start the idle is 2500rpm. Two hours later back at my garage it's 3000rpm.
Any ideas what is going on?
Can't see any obvious vac leaks, hosework looks ok.
Tested the IACV power supply. 12V. Ok
Tested the IACV resistance. 10 Ohms. Ok.
Unplug the IACV and the revs drop off around 400rpm.
Unplug the TPS and there's no difference.
As the car warms the revs are very very gradually wearing off but I can't sit at 3k rpm in the garage. And I'm reluctant to play with the IACV idle screw as the idle has been fine since mapping.
Any ideas are welcomed.