Porsche 930 engine trouble.

[Horneck]

The engine of my 87 930 stopped running suddenly in front of a traffic light. When I tried to restart the engine two big booms in the exhaust were noticeable but not even a single ignition was noticeable.
I towed the car home and try to start it in my garage and suddenly the car started right up. This morning I tried to start the car and again the engine refuses to start.
What should I check to find the fault? My engine has only 58k miles and was always very reliable. Is there a way to read out error codes to find the problem?
Appreciate the groups feedback.

[gsxrken]

As these cars approach 40 years old, it’s the years and not the mileage that cause more problems.
There are no computer codes on these cars.
Your answer lies in this thread somewhere: https://forums.pelicanparts.com/911-930-turbo-super-charging-forum/547032-sticky-common-answers-why-my-car-doesnt-start.html

A systematic approach fuel, spark, wiring will eventually uncover the issue. The ass-kickers are when it’s intermittent… that’s usually a dirty electrical terminal somewhere (often under the strivers seat on the speed relay.
Good luck with your analysis and come back and tell us what you found. We’ve all been there.

[icemann427]

Check out the two below threads that are near the bottom of this first page (911/930 Turbo & Super Charging):

1.) New to me 1987 No Start Issue

2.) Car Shutdown

[reclino]

Sounds like an ignition problem, test for spark. Are you still running the Bosch CDI ignition?

[Horneck]

I have checked my engine management system and have identified a weak and irregular spark at the coil. Will measure the coil tomorrow. I have exchanged a rebuild CDI with my own CDI but no improvement of the spark at the coil. What other components can lead to a very weak spark?
Thanks for your feedback.

[reclino]

Get a MSD high vibration coil, should be available at your local parts store, they are available in red or black. It will work with the Bosch CDI. Coils do not last forever, the original coil.with it's PCB tar like insulation is very durable, but aftermarket coils can be considered as consumables.

[Axel84]

or get a Classic Retrofit CDI box - they are brilliant.

often ignition issues, and people start troubleshooting the CIS!

[Horneck]

I have gotten a used Bosch CDI and Coil from a friend to test my system and now I am not able to get any spark?
I was able to test voltage at the white wire of my coil with no spark but now even that voltage is no longer present.
Appreciate further ideas what to check.
Thanks

.”

[john walker's workshop]

Bypass the delayed ignition cutoff relay for test purposes. Jump the plug. CD unit won't get power if it fails.

[Horneck]

I start to wonder if my issue is the famous “Green Wire” but my wiring harnesses does not have the female connector to replace with a the short green cable.
Is there a female pigtail connector available that I can try to splice into my CDI wiring harness?

[mikedsilva]

Originally Posted by Horneck

I start to wonder if my issue is the famous “Green Wire” but my wiring harnesses does not have the female connector to replace with a the short green cable.
Is there a female pigtail connector available that I can try to splice into my CDI wiring harness?

try giving it a wiggle while its running, the next time it starts.. or wiggle it while someone turns the key.. wear ear protection

[flightlead404]

Originally Posted by Horneck

I start to wonder if my issue is the famous “Green Wire” but my wiring harnesses does not have the female connector to replace with a the short green cable.
Is there a female pigtail connector available that I can try to splice into my CDI wiring harness?

You have to start peeling back the covering from the harness starting at the distributor following the green wire until you find a place where the wire insulation is unburnt and not too brittle to allow a good splice.

I believe there are two options for green wire replacement. One has a much longer length of wire than the other. I believe that is labeled as for the 928, but its the same wire/connector.

[feraripeter1]

Check the ignition...

[flightlead404]

If you end up needing it, I have a working CDI from an '86 930 and two working coils for sale.

If not, perhaps one of these Dubai call girls can help troubleshoot it...

[infraredcalvin]

Originally Posted by flightlead404

You have to start peeling back the covering from the harness starting at the distributor following the green wire until you find a place where the wire insulation is unburnt and not too brittle to allow a good splice.

I believe there are two options for green wire replacement. One has a much longer length of wire than the other. I believe that is labeled as for the 928, but its the same wire/connector.

Somebody please correct me if im wrong, but If I recall correctly the green wire you mention (labeled for the 928) is backwards, i think i remember pulling the wires out of the connector and swapping the pin location for mine.

I have a ‘76 so some things may be different, but I thought i’d mention it…

[flightlead404]

Originally Posted by infraredcalvin

Somebody please correct me if im wrong, but If I recall correctly the green wire you mention (labeled for the 928) is backwards, i think i remember pulling the wires out of the connector and swapping the pin location for mine.

I have a ‘76 so some things may be different, but I thought i’d mention it…

I don't remember doing that, but it was years ago and I have electronic ignition now.

[Alan L]

I just had issues with my green wire.
You first need to check the connection ohms at the CDI plug. Terminals 31d and 7. At end of plug - one above the other. Hard to derscribe which end if you don't have diag, but nothing lost. One end should give about 600 ohm - top/bottom pins. If you don't get this you have an issue with either the coil in the dizzy or the wire.
As the plug end faces you the probes will go in the LHS pins - top/bottom. 600 ohm across them,
Post results and we can proceed from there.
Alan