d15b7 block with z6 head, virgin p28.

I've been having this low idle around 300 after the car is warmed up and I've cleaned out the IACV and left it unplugged while adjusting the idle screw. It had no effect on the idle AT ALL. I did everything after the car was fully warmed up and after the fans came on. I've searched all over and the only mention is cleaning the IACV. The IACV doesn't look that bad/dirty and I'll try to swap it out with another to see if it's bad. Coolant is new and bled properly. What else can I do to resolve this low idle issue?

 

first off, in order for it to idle at 300 you would need to be below the very little line right above off. that line represents 500 rpms.

I have the same problem. I need to do a timing belt on my car yet and change the plugs and wires. That will solve my problem.

When this happened before it was due to the MAP sensor. It was not hooked up correctly and was reading the pressure outside of the manifold which created a very low idle rpm. Check the MAP sensor and TPS sensor and make sure they are not connected in the wrong place.