Well was working on my AC system today. I got it working, Got heat working as well, but yu guessed it, a new problem popped up today. Here are the symptoms.

Idle - stable. perfect in drive, increases to 1-1.2K in park
Acceleration - No issues
Decel - No issues
Cruising at fixed throttle position, rpms will oscillate -100 or -200 rpms, then back to prior will do so in about a 1 sec time frame.
turn on AC, behavior is gone, and seems to work well.

Stop at light and go, issue goes away for a bit, but then seems to switch on and will start erratic rpms.

Other thing that happened to me today, got my temp11 switch, installed it, but did not realize I still had pressure in the coolant system. Some coolant leaked out.

There is a vacuum switch below that probably got wet. Not sure what the switch does, been trying to find a name for it. May be my problem.

thanks for the help again... rr

 

Well I unplugged that vacuum valve i the left front of the engine bay, and that may be my problem. Running much better. Also conformed I have my temp II readings to the ECU back, so will have to try to do an adaptation. Still open to suggestions though/ I want to go to Sharks in the mt this year. For the past 4 years, something like this came up and I bailed. So wish me luck

 

There's no vacuum solenoid under the Temp II switch. The flappy solenoid lives under the Temp I sensor/Temp sending sensor on the driver's side of the bridge.

 

Going to need to take a picture. this one is just to the side of the distributor cap. Will post tomorrow.