My H23a does not like to stay on when i 1st start it. I'll have to hold on the gas a bit to keep it idling till the needle starts to rise. Once it's warmed up it runs fine though.

I'm wondering what could cause this. I know the 02 sensor is fine, so it isn't an issue with the car being on cold cycle. I also noticed that my brake booster is bad, which i had to notch to fit my Skunk2 IM on. I believe the check valve inside is dead or the booster itself is leaking, either way there's a serious vacuum leak there. I can tell because there's no reserve vacuum when stepping on the brake and the pedal gets hard 1/2 way pressed. Could that be the reason why the car won't idle properly when cold?

 

any opinions AT ALL?

 

I would guess your fast idle thermo valve maybe? Second opinions?

 

where would that be located? how would i check it? I have a skunk2 70mm TB and IM

 

I am not familiar with the skunk2, but normally there are two valves involved. The cold air valve is at the bottom of the intake on the passenger side, right where the plastic intake tube connects to the metal manifold. There is also the Intake Air Valve that controls idle as loads such as electrical or airconditioning are placed on the engine at low speed. It is on the front of the intake manifold right in the center. It has three bolts to hold it on and there is a 3/8 or so hot water line running to it.

The cold air valve (CAV) has a special temperature sensitive wax that expands as it gets hot. There is a small hole that allows air past the throttle plate until the wax valve swells enough to block the air. There is a screw on the bottom that causes no end of idle fluctuation problems if it is loose - now is a good time to check it. It is likely that the wax retaining screw is loose, or the bypass passage way is plugged.

Watch the water lines when you remove them on the IAV on the front of the manifold. Anyway, one side of the IAV has a fine mesh screen and mine was completely gunked over with oil and dirt. It spend the night in a WD-40 bath and then got a good scrubbing in the morning. Now it works great.