I'm writing this because I've been driving for about 5 years on my Brainsquirt MS1 that's in parallel with my '96 stock ECU. It hasn't ever had a problem and everything's always been great.

This summer it hasn't been idling well with the AC. Last year it was fine. Now sometimes it idles up around 950-1000 and runs perfectly smooth but then it will drop down to ~650 and be really rough and sometimes die. I believe with the parallel install the stock ECU is supposed to control the idle? If this is the case where should I start looking? I've had problems before when leaving my car out in the rain and the wires to the ECUs got corroded, but that was easy to fix. I'm wondering if maybe there's another broken wire. I changed the fuel and timing and it idles a little better but still not great.

Any advice would be welcome!

 

sounds like the stock ECU isn't kicking up the idle?

 

Yeah I think that's the problem but I'm not sure where to start looking.

 

maybe the idle valve is bad all together? does the idle change when you unplug the valve? it should jump up a bit.

 

Well I feel dumb. I had replaced the stock IAC hose with just some generic hose because it cracked, and the replacement hose developed a kink because of the twist. Removed the hose and the car idles perfect.