RB20DET
After cleaning and re-installing the AAC Valve, the idle now sits at 1400rpm, higher when cold. Before cleaning the valve, the idle was 800-900rpm.
I have spent days reading through posts and trying to find a solution.
So far I have tried...
1. Adjusting idle screw (turned all the way in)
2. Reset ECU
3. Removed and cleaned IAC Valve
4. Re-gapped spark plugs to 0.8mm
5. Insulated coil packs with silicone
6. Checked all lines and connectors
After cleaning the IAC Valve last night, this morning the car was idling at 2000rpm all the way to work. It finally dropped after driving for 20 mins to 1600rpm. I noticed the spring inside was not fully closing the valve, obviously allowing some air to enter on idle. I presume this may contribute to the problem.
The only other problems I can think of is;
1. Gasket on AAC valve is faulty
2. Vac leak in or around plenum/manifold
3. Faulty TPS
I thought I might try adjusting the CAS but I wanted to post here first to see if anybody might be able to pinpoint the problem.
Any help would be appreciated, cheers.