86944T

Well this is frustrating,
My '86 951 went into the shop about a week ago to get new motor mounts, and new ball joints put on. Control arms were sent out to be rebuilt, and the car was at the shop for a week. Car was pulled down off the lift to goto the alignment shop. It was started, pulle dback about 10 feet and then died. Car was restarted and ran for about 30 seconds, and then died. Has yes to start again.

Mechanic says fuel looks good, the car turns over fine, but we have no spark. New DME relay was ordered, and put into the car this morning with no luck. Here are possibilities that the mechanic and I have come up with:

1) Old alarm system that is installed in the car. It is ancient(circa 1995), and barely works(all it is used for is power door locks). There is a fuse for it that was removed, but this did not help.

2) DME / Coil gone bad?
3) Speed reference sensor

Any ideas guys? This is pretty much brand new, the car has always started just fine.

Any help would be appreciated.

Peter

Waterguy

I would say that your mechanic had it about right. Couple of suggestions:

1. Verify that your camshaft is turning (timing belt.)
2. Check that your rotor has not come loose inside the distributor cap.
3. Jumper your alarm: Unplug the alarm control box and jumper wires 1 to 4 and 7 to 8 on the plug. This will bypass your alarm.
4. Check all your electrical connections especially the plugs to your speed and reference sensors.

Next up would be to check your speed and reference sensors, then your coil, then DME.

86944T

Don,
Thanks for the suggestions. Any idea on the best way to jumper the alarm? Just use standard wire? The car isn't in front of me, but if I remember correctly the alarm uses a long flat plug that is about 3-4 inches long x 1.5 inches wide.

I believe the cam is turning, I will check on that.......Hopefully the timing belt didn't let go.

Thanks again for the help.

Peter

Dales944

I've had experience w/ #3 above, but I'm not sure of the diff's between an early N/A and your car.

Immediately after having my clutch changed, my car ran HORRIBLY. It would cut out, die, not start, then maybe the next day it would start.

Anyway, my sensors were well connected at the housing (where the two Micky Mouse looking connections are). I traced the wires from there and there was a harness held together with a "three-sided rectangular clip type thing" that was loose. I plugged the ends back up and fixed the clip into the grove and all was excellent afterward.

Someone posted a pic of the connection of which I speak.

HTH.

Robert D

If the timing belt let go, you would hear a difference. The crank would be spinning and by itself would make a higher pitch noise (happened to me). If it is turning over and sounds normal, I doubt the belt broke.

seb928s

Hmm when I rebuilt the head on my 1986 951 I had a no start problem.
1. Check to see if the boost needle is at 1 bar when you put your key in right before it cranks. If not then it's something to do with the DME.

2. Check the coil and the line to it. I had a no start problem with that on the 924S when I rebuilt the head on it everything looked fine but the coil was bad and the wire going to it.

3. On the 86 951 I that didn't want to start turns out a wire that connects the DME relay in the fuse box broke and it needed to be connected.

4. Sensors on the bell housing could have been damaged or loosen during the engine work doesn't take too much to do that, esp if they are old.

Check all the cheap items first. Hope you find your problem and let us know what it was.

jd944

Call me crazy but I'd say it has something to do with the motor mount install. I'm sure they had to lift the motor to replace the mounts. They may have inadvertantly loosend one of the crankshaft reference sensor plugs. They are also damaged quite easily. Definately woth a look.

Yabo

check plug gaps.. mine were .1 off, and it had trouble starting ,, i m thinking thats what it mightve been. although this is not it right because you said it doesnt get spark, from teh distributor?

Peckster

The alarm system is not stock, right? That advice was for a stock system.

sm

Was the steering rack dropped to do the motor mounts and A-arms? If so, ensure that the wire which is attached to the steering rack with a screw is indeed attached.

86944T

sm,
Yes, I do believe the steering rack was dropped in the install.....I will have them check that.

Thanks to everyone that offerred suggestions, I will pass them on. I will also let everyone know what the problem was when it is resolved.

Thanks,

Peter