No Spark issue HELP 8V 2.5L 924S
 

I have a 924S that is giving me some trouble. I have a signal processed from the DME since the Injectors are firing as required and the DME relay and fuel pump is working fine... The fuel system is all confirmed.

For spark, I replaced the coil with a known good one and replaced the cap and rotor but it seems the non-spark is being caused by a fuse/Computer/loose connection under the dash (where all this is located on the 924S.)

Any suggestions would be a great help. It seems I can get it started if wiggle wires/tap on Computer and roll fuses under the dash. But it will cut out and quit when it feels like it.

Any advice or help would be appreciated.

Aaron
atsudds@cogeco.ca

Check the inside of the computer for soldering issues at the ribbon(grey wire loom).

Dal

Is it a common issue for the DME to fail... If so I'll try swapping it with another one.

Aaron

Not often but does. The ribbon is a known area to break.

Dal

To check that it is a DME problem rather that a wiring problem run a jumper from the batteries positive terminal to terminal #15 (black wire) on the coil and see it it will spark.

SoCal, can I run a jumper and drive it that way in case of emergency?
Does the DME do anything more than provide a 12V supply to the Coil? Like I said, the injector pulse seems to be firing ok.

Thanks,

Aaron

The DME provides the ground and allows the system to run. Sounds like you need to both thoroughly check the wiring and if ok, substitute a DME.

Swapped the computer with a known good one... so far so good...

I'll try and fix the old one.

Aaron

If the problem recurs, it may be the ignition switch. I had a similar experience with my 924S and wound up wiring a toggle switch across two of the ignition switch poles. (I was at Sebring for a PCA race.) Five years later, the toggle switch still works.

DME had obvious cold soldier joints on the power transistors. Must have been the problem....