Idle Speed Motor Problems: I made it worse by cleaning it?????

[DMCVegas]

That is great progress!

Now the next question is where is your original ISM? Is it still intact, and does it bench test fine as well? If so, you could return the new unit to get your money back.

[RamblinDMC]

That is great progress!

Now the next question is where is your original ISM? Is it still intact, and does it bench test fine as well? If so, you could return the new unit to get your money back.

No, it was seized and no amount of carb cleaner would free it, I disassembled it to attempt to fix it, but ended up screwing it up. I didn't pay much for the 501.

[nkemp]

A 6-8V pwm signal can be seen on the ISM plug with it unplugged.

Just to be clear... you are measuring between center and the outside pins. And you are seeing 6-8V on both sides?

[RamblinDMC]

Just to be clear... you are measuring between center and the outside pins. And you are seeing 6-8V on both sides?

Yes that's correct. But once it's put under load, the voltage drops away.

Thanks

[RamblinDMC]

I'm currently placing an order on Mouser to replace the diodes, ICs, transistors, and electrolytic capacitors. Having a tough time identifying the diodes. Is there a schematic and parts list available?

[RamblinDMC]

Update:

I was able to trade some machining/fabrication to another DeLorean owner in return for a good used idle ECU. Everything on my car works as intended now! Turns out the 501 ISM isn't wired backwards. Not sure what I was thinking there!

I'm still waiting on the parts to repair my old ECU, I'll still try to fix it just to see if I can do it.

[Elvis]

80% are the power stages. done.

how to test a transistor is most likely all you need to know.