It ran, then it didn't

mikekirby · mikekirby's Garage

Over the past few years I have been working on my 1983 944. It was bought as a non-runner, and after going through everything I was finally able to get it fired up and running two weeks ago. Turns out i have the spark plug wires in the wrong order. After it started and we got it running I took it for its first run in 9 years. Then parked it for a week. Nothing changed, no one touched the car until I returned Saturday June 1st. Then nothing. No spark, no juice to the injectors. The fuel pump buzzes and we have fuel at the end of the fuel rail.

At this point I am thinking it is a bad ground. Does anyone have any other ideas as to what I should look at/for?

Also the drivers side low beam headlight does not work. Fuses are good and we tested the headlight and the headlight is good on both high and low. Does the wiring loom go between the two headlights? I will admit that my ability to read wiring diagrams is terrible.

I thank you all for any and all guidance you can give.

Mike

CarGuyNeil · 06-03-2019, 04:40 AM

This is from someone else buy may be helpful, the ground chart.

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mytrplseven · mytrplseven's Garage

Just to be sure, what's the battery condition?

Jfrahm · 06-03-2019, 05:24 AM

It's hard to tell but it sounds like it's cranking but not starting? If it was not cranking you would not care about injectors and spark.

I suppose you already checked for tach bounce and tried a simple DME relay jumper as per Clark's garage. After that if you have tach bounce a puff of starting fluid or dribble of gas in the intake is a good test. You say you have no spark but it's always good to test your assumptions.

-Joel.

mikekirby · mikekirby's Garage

Hi guys;
Thanks for the feedback. Answer to the questions posed.

Mytrplseven: Battery was out of the car on charge, when installed it was a full charge and started the car May 25th. To be sure we jumped it with a known good one from another car.

Jfrahm: We swapped in a new DME relay. Car cranks, when we pulled the plug wire and connected a spark plug to check for spark on the intake, we got nothing. Tach does bounce. We also swapped in a test DME. Although I didn't test with starter fluid, we do have fuel at the end of the fuel rail.

Neil: Thank you for the location of the grounds, I will be spending a good bit of time going through those on my next visit to the car.

mikekirby · mikekirby's Garage

We diagnosed the problem with the car today. It is the DME itself that went bad. At K&B Auto today there was an '84 944 sitting next to mine. It was strategically placed. This car is a runner and was in for some simple maintenance. We swapped my DME into that car, and No Start. So we now know for sure that the DME is bad. This was after we cleaned the DME ground, and the main ground. After doing all that we sawpped in new window switches, and the windows now go up and down from both sides, made sure that we had the exhaust hung with the middle rubber to ensure it does not rattle, and finally added the sway bar brackets to make certain that does not fall off. Slowly we are getting there and will get this car back on the road again after 10 years.