1984 944 help

[billygoat]

have been trying to get running sat for a good while new ingnition switch new fuel pump relay new dme . no spark at coil and no power to coil and no fire at plugs does dme need to be grounded what else could it be

[fiat22turbo]

This might help:

Pelican Parts: Porsche 924/944 Electrical Diagrams

and:

http://www.clarks-garage.com/shop-manual/ts-01.htm#fire

More specifically on Ignition troubleshooting:

http://www.clarks-garage.com/shop-manual/ign-04.htm

and then troubleshooting the fuel system and the DME relay, etc:

http://www.clarks-garage.com/shop-manual/fuel-16.htm

My suspicion? An electrical problem with the melted wiring you mentioned before or an issue with the flywheel sensors or just a bad DME relay. Do the diagnostics listed above in the links and see where you end up. You have to do all of them, one by one, no skipping around, etc.

[Dave Colangelo]

I had a similar problem with my 924S (same motor) and it turned out to be the DME unit. There are a few things I would do...

1) clean all your grounds.
This is a common issue, they corrode over time and can cause the electronics to freak out.

2) test for continuity
Make sure that the wire from the coil is in conducting condition. I dont remember the pin out exactly but you can disconnect the DME unit (look up the pin out) and make a simple circuit tester to make sure the wire is from the comp to the coil is ok.

3) make sure your sensors work
There are 2 sensors in the engine that drive the DME. These sensors are notorious for going bad. They are located between the engine and clutch housing I believe. If these are bad your DME will be getting no timing info and will not know when to pulse the coil

4) Check your coil, distro cap, and rotor
Make sure your rotor is aligned correctly (can be checked at TDC) and free of corrosion same goes for your distro cap. Check your ignition wires as well.

5) New DME?
where did it come from? did some one rebuild an old one? was it one of a working car? was it an untested one? Depending on how you got this the DME could be toast. to confirm this you would really need an oscilloscope to check the signal at the coil. A multi meter is not enough as its a square wave not a constant voltage.

6) check your fuses
The DME may just not be getting any power

Regards
Dave

[billygoat]

has power to dme does hot at coil become hot with just key on acc