930 Starts Runs and Dies

[Bgravolet]

Thanks to everyone who gave the help to get my car this far. My 1987 930 was running, lost power and died. It refused to restart.

It took weeks of going from one component to the next to try and find the problem. The thermo time switch was disconnected, the Perma-Tune box was bad - we replaced it and the coil, the overboost relay was cooked, both fuel pump relays were bad. I even changed the speed relay but it had no effect.

Yes, hard to believe but they were all bad - makes me think an electrical issue...

Now it starts and runs for 8 to 10 seconds and dies. The tach jumps around wildly and usually stays around 6000 to 7000 rpm although the engine is stumbling on itself.

Any ideas? I'm almost out of them...

Any advice would be appreciated.

Ben

[PrimeMvr]

Sounds like your voltage regulator is shot. That can fry your list of items and definitely cause the tach behavior. It may have cooked a fuel pump or is playing havoc with them causing your stumbling.

I replaced mine this spring and it's about an hour job.

[mark houghton]

Originally Posted by PrimeMvr

Sounds like your voltage regulator is shot. That can fry your list of items and definitely cause the tach behavior. It may have cooked a fuel pump or is playing havoc with them causing your stumbling.

I replaced mine this spring and it's about an hour job.

+1. It's not a huge difficult job to replace it. Next time you start her up (for 10 seconds run time or whatever), slap a volt meter on the battery terminals and see what the voltage is doing. Might point you in some direction. Also, make sure the single fuse that protects both pumps is clean and well seated.

[JFairman]

If you have AC give yourself a couple hours. You have to remove the fan housing to get to the voltage regulator on the back of the alternator. It's the black plastic thing towards the top in this pic.

While you're in there you may want to clean the positive, ground, and exciter wires and replace any corroded terminals and dried out rubber boots that cover them and smear some dielectric grease on the wire terminals to protect them from rain water.

[Bgravolet]

Thank you all so much! I'm leaving town for a few days but will order one and replace it as soon as I get back. This has been so frustrating I'm pilling out what little hair I have left!

Ben

[klefroid]

Originally Posted by mark houghton

+1. It's not a huge difficult job to replace it. Next time you start her up (for 10 seconds run time or whatever), slap a volt meter on the battery terminals and see what the voltage is doing. Might point you in some direction. Also, make sure the single fuse that protects both pumps is clean and well seated.

+1. You should read +- 14 to 14.7 volts engine running

[bolt]

yep! to give you some confidence in case you need it....not a difficult job at all! In fact it was probably the first thing I had to tackle myself shortly after acquiring the car.