I parked my 1984s auto a few months back. It was running great. It sat for a couple of months and now it will not run. It cranks over fine and tries to start but as soon as I release the ignition key it goes dead. It has a new fuel pump relay and fuel injector relay and good fuel pressure. It seems to stop firing when I release the switch.I hooked a test light to the positive side of the coil to see if it was getting power when I released the key. It cranked right up and ran fine with the test light hooked up. I disconnected the test light and it continued to run. I shut it off and it reverted to the earlier behavior. It runs with the test light hooked up but no light no run. It seems to need that little bit of resistance to keep the coil firing after cranking. Is there a resistor in that coil circuit that could have failed?
Any suggestions would be appreciated.

 

I think there are two resistors. One for cranking and one for running maybe. Cannot find a picture of them, but here is a diagram:
https://rennlist.com/forums/928-foru...resistors.html
They are on the fender wall near the coil, I think.

 

Thanks. I'll check it out in the morning

 

Are these the two resistors your referring to ?

Ken
80 928S
5 Speed
UK

 

That is them.

 

Thanks. I found them where you said they would be hiding. Beru WZR-04K and Beru WZR-06K
I wonder if Roger has them.

 

He and Mark A both keep Mercedes alternatives in stock since the original ones went NLA years ago. They're cheap to replace as well.

You can test to see if they went bad by bypassing them. If the car keeps running, you've found your culprit.

Just don't run the car with them bypassed for extended periods of time as the coil will get cooked...

 

Thanks