bdellis

I have been unable to crank my car for several weeks now. I replaced the plugs, wires, rotor and coil. It was time so I went ahead and did this but still the car turns over but never fires. I picked up a spark tester and tested fire at the plugs. No luck. The distributor, no luck and now even at the coil. NO fire? Where do I go from here? Hard wire the coil? I have not had do deal with this type of problem in the past, although I am certainly not afraid to "break" the car. It already will not crank.
Is there something simple I might be missing? Could it be that the wire leading to the coil is corroded?

Any ideas would be greatly appreciated.

Thanks,

livewirevoodoo

Does the tach bounce? If not, could be your speed and reference sensors... otherwise...

I would look at the fuel system. Fuel pump, pressure regulator, fuel injectors. Verify those are in working order. Could be any of those parts, or a relay, or a fuse...

944Ecology

Use the factory service manual diagnostic procedure (located under Ignition) to diagnose your no start problem.

There are quite a few things that could cause it, including, but not limited to: DME, DME relay, wiring, grounds, voltage, fuel pressure, flywheel sensors, and even more.

If you don't have a systematic, organized approach to diagnosing the problem, you could spend a long time trying a bunch of different things.

I have never failed to find the source of a no start problem using the diagnostic procedure.

bdellis

Yea, I have the car in my garage right next to a running 86 N/A. I have been using my manual to try and have a good appraoach? The Tach does bounce so the ref sensors are probably good. In fact they appear to be in some of the best physical shape of any I have seen on my cars. I have 2 86's A turbo and a Non turbo and this one 87 N/A and an 88Trubo S.
I have swapped around all the things I can think out outside pulling up the passenger carpet and putting my 86 DME in the 87.
As far as the fuel system goes, It appears to be ok. I am certain no fire is getting to the engine because the wire from the plug to the distributor does not get fire. I tried a known "GOOD" wire from my 86. And an known "GOOD" coil from the 86? For some reason the COIL is not getting power? I see where the headlight get a seperate power cable that splits off the main cable which attaches to the coil. And Yes, My headlights do work, the motor works and the lights. In fact all lights work? So I am sort of stuch here? Should I try and pull parts fromt he good 86. I hate doing that in the event I ned up with two cars that do not crank rather than 1.

944Ecology

For a go/no go test, you can put your NA DME in one of your working turbo cars. If that works, then your DME is OK.

If that doesn't work, I suggest you follow the factory diagnostic... It will eliminate every possibility until you find the problem... I know it takes a long time, but a methodical approach is what you need now.

gb

Tom Carson

with the ignition key turned on (run position, not start) +12 volts is fed from the key switch on the thin black wire to the coil terminal.

a 12 volt test light connected to the chassis and that thin black wire will light if the 12 volts is present. if it's not there your ignition switch (or the black wire from it) could be bad.

as the engine is cranked during starting the DME unit sends a ground pulse to the other coil terminal on the green wire. (it’s that ground pulse that causes the spark voltage from the coil.)

move the test light from the black wire to the green wire and you should be able to see the light solid with the key on…

and the light should pulse on and off as engine is cranking during starting. if not your DME unit (or the green wire from it) could be bad.