Idle Speed RPM Issue - Video Attached
Any insight or assistance would be very much appreciated. I'm having an issue with the idle speed system with the A/C on or off. Dwell is on point and in range, well as best as I can as I am running open loop.
The car has always had issues under an electrical load. Accelerating there is no issue the car pulls like a train. The car seems to dip upon when revving the engine and returning to idle. For example while revving the engine with the A/C on you really notice a dip in the RPM as if it was about to stall and right before it does the RPM system seems to catch it. Almost coming back to idle. If you look at the video for example the issue I am having as of right now is as follows:
Car while start fine and idle for a bit then start going into a surging idle issue. If I disengage the ISM via its electrical connection the issue goes away as if everything is working perfectly. Also, I can back out the top adjustment screw and the idle will shoot up as if the ISM is connected. I can press the micro switch and idle will come down. Of course the ISM has to be connected because it should managing the idle system. Also if I try connecting the 02 sensor to activate the Lambda system this issue is the same and worse causing the engine to stall. This is kind of where I am right now. I don't know if the idle speed thermistor is the cause. I can post more videos if possible and needed.
https://youtu.be/fRdx5tVTu4I