[mikew968]

I am having quitting issues with the 968 while idling and when running on track at speed. It is getting worse and seems to be related to heat. I never had issues before this season and the following were done to the car over the winter: fendenza flywheel, motor mounts, rod bearings, cam timing, magnecor wires and coil, some engine sealing issues.



I have been able to be check the green wire to the coil (goes to the DME) and after the engine stalls there is no voltage for about 10-20 seconds and then the wire have battery voltage agian and the engine will start back up.



First-up any ideas

Second...what can cause the DME to shut off power to the coil?



Thanks for the help as this is getting to be a real pain in the A$$ and expensive as well.



Mike

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[flash]

have you done the obvious swap of a new dme relay?



failing that, swap the coil and wires back out to something else and test that - i doubt it's there, but it's easy to test

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[rustech]

The ignition switch comes to mind, try turning it on then jiggling the key a bit to see if it cuts out (I'm not sure how heat would effect it). I would also reseat all of the fuses and relays associated with power to the ignition and the start/run systems. Good luck figuring it out.



Flash, I think Mike is referring to the coil input, not the output.

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[mikew968]

I am actually going to change back to the old coil just to make sure but yes it is the input wire that is the problem orso it seems. I have jiggled the ignition key and nothing changes but it is definetly something to keep an eye on.



Thanks, Mike

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[jpk]

I'd start suspecting the DME itself. A cold solder joint could be cutting off power to a transistor.

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[flash]

as i said, i tend not to suspect the coil or wires, but it is a simple thing to test by swapping out - a dead short in the coil (which i had once on another car) can cause relays to trip



did you swap out the dme relay with a new one? don't trust one just because - try a known working one

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[mikew968]

The dem relay has been swapped out with 2 new ones and has also been bypassed with jumper wires to no luck. I am going to install the old coil and if no luck with install a new reference sensor. If that doesn't do it then I am starting to think the DME.



Mike

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[flash]

i'd clean the contacts with contact cleaner first before risking an issue with a new dme - as eric suggested, i would include the ignition switch in that cleaning process



it may well be the dme, but i would eliminate all of the simple things i could first



have any fault codes popped up on a blink test?

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[mikew968]

At this point it looks like the new coil was bad. i put the stock coil back on and everything ran fine. Swapped back out and it quit again. A lot of frustration but in the end a relatively simply solution.



Mike

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