no spark

[armandodiaz]

Thanks Loren that's the answer I've been asking for. I did find it strange that I had +12V on the pos side of the coil, a pulsating +12V while cranking on the neg side but still no spark. Kind of takes the ref and speed sensors out of the trouble list.

[rick-l]

Originally posted by armandodiaz
Kind of takes the ref and speed sensors out of the trouble list.

And narrows it down to coil, dist and wires/plugs

[Lorenfb]

As I said, from the coil wire to the block = 25mm spark.

[armandodiaz]

Well you guys aren't going to believe this. I got my coil today. Of course I'm not that lucky that it would have been something as simple as that. But it was a good, cheap and logical try.
I proceeded to #2 on my list the sensors. Even though I didn't have new ones I thought let me take a look at them. Since I installed solid mounts on my car, maybe they came loose. I was 1/2 right. The bolt on the speed sensor was rusted off and the ref sensor was loose. You may think that this was my bad lucks doing. But it was actually from someone butchering the car before me. After removing the bracket I proceeded to take the sensors off and clean everything. I have a broken stud removal kit but the broken bolt would not move, not even with heat. What the removal kit help me do was find the middle part of the bolt and drill right down the middle. I worked my through the bits until I got to the right size(3/16) I then tapped out the hole and whalla. Still thinking why am I calling the last person a butcher?
Just to test the threads I put in the sensor and the one remaining bolt. The other bolt bottomed out before it ever touched the sensor. So what I'm guessing happened was the one bolt bottomed out the butcher kepted tightening it until it broke. He didn't want to take it apart and drill it so he put the one sensor in and on the other sensor he tighten the bolt until it bottomed out. I'm just surprised the car ever ran at all. Going back to my theory up top I guess it was in its place until I installed the solid mounts and rattled everything.
Tomorrow I will finish putting everything back together and hope it runs. If not I will problably buy new sensors.
Lets hand it to the boys at Porsche for building a car that will run no matter "WHAT" works on it.
I'll keep you posted Thanks everyone for all you help.

[Lorenfb]

If you got a signal at the coil, the ref & speed sensors are O.K.
You should NOT be fooling with the sensors. If the pulse is good on
the coil, then you should be getting a 25mm spark out of the coil
wire unless it's bad. Have you checked for injector pulses?

You're taking the "shotgun approach" to solving your problem which
wastes time and money, and may also cause another problem. As I said,
troublshooting a 3.2 starting problem is simple.

The count:

1. New DME relay
2. Opened DME unit & separated boards with possible damage
to boards causing present/future problems.
3. Bought new coil.
4. Removed & reinstalled sensors with possible mix up of sensors.
5. Possible purchase of new sensors

[armandodiaz]

Yes there is a pulse at the injectors and coil. But how can you expect me to not mess with the sensors if one has a broken bolt and the other is sitting in the bracket loose? Don't you think this would be an obvious area to work on?
You do bring up a good point about the coil wire. I know to check it you suppose to put an Ohm meter to each end. Does anybody know the value of resistance?

[Lorenfb]

Yes, you need to eventually fix the sensors' mounting, but you should fix
the "No Start" problem first.

The resistance is dependent on the wire. Most (non-resistive) should have
zero ohms. A resistive wire should have 1K to 2K ohms.

[koollay]

Armando.......anything yet?

[armandodiaz]

Yes I just finished fixing it today. One lesson that everybody and their mother always tell you, "Go with your first instinct." I should have listened. My first option was the reference sensor. Since I had power at the coil, I second-guessed myself and went with the cheaper part. After that didn't work, I moved back to the sensors. I saw the nightmare someone performed on the sensors before and went with the obvious, fix the broken bolt and correctly adjust the bracket back onto the engine. Although this didn't fix the problem, it did give me a solid reading on my voltmeter. I got a .05 reading on my speed sensor and .00 on my ref sensor. Since both sensors are identical I switched the ref to the speed (make sure you switch the plugs also) then I got .05 at the ref and .00 at the speed. This time I was positive one of the sensors was bad. I changed both sensors anyway and kept the good one as a spare and cut the wire off the bad one and will use it for future adjustments.
I originally wanted to just buy all three parts but I was convinced into tracking down the bad part. Even though it gave me much insight into diagnosing the Motronic System, my boss didn't appreciate my coming in about 1/2 late to work everyday for a week because I had to bum a ride from a neighbor. If I would have only changed the bad part it would have cost me about $100.00 and possibly getting stuck again because of a 19yr old coil and/or speed sensor. Total cost:

Tow : $125.00
Coil : $50.00
Sp sensor: $100.00
Ref sensor: $100.00
Bottle of Bacardi (to forget about the past week) $19.00

Thanks all and I hope this tread helps others.