mhpd31

Hello, I have a 1988 944 turbo S. She was running great when I parked her in September for the season. She was parked in a climate controlled garage with a cover on. When I pulled her out last week the battery was dead, put the charger on and tried to start, but there is no spark. I got on the forums and tried to trace known issues, but so far no luck. The tach does bounce when turning over, I replaced the coil, getting 12 volts to both the green and the black wires on the coil with the key on, fluctuating voltage on the green wire while turning her over. However I am not getting spark from the coil to the distributor cap. I tested this both with a tester and by putting a plug in the distributor side of the coil wire. I am at a loss and could really use some guidance on which direction to go next.....

Paul Waterloo

Did you pull the cap and inspect the rotor and cap?

mhpd31

I did, rotor, cap and wires only have about a thousand miles on them. Pulled the cap and everything looked fine.

Paul Waterloo

Sorry, I read your original post wrong.....you said that right in there.

mhpd31

No problem, thanks for the suggestion.

Adker

Try tapping the green wire to ground with the ignition on, this should generate a spark from the coil. If it does, the DME may have a bad driver that isn't pulsing the green line a volt or two from ground (darlington driver). Be careful of the black wire, it goes directly to the ignition switch and is not fused. Short it to ground and you get smoke.

Tom M'Guinn

When you turn on the ignition, does the boost gauge go to 1? If not, and instead the boost gauge doesn't move at all, your DME is likely not getting power, probably from a winter-stuck DME relay.

mhpd31

Ok, coil is definitely good. But the boost gauge does NOT move when I turn on the key, tach does bounce when cranking but the boost gauge does not move at all. I don't have a spare relay, so I am getting ready to order a couple online. Here is to hoping that fixes the problem. Thank you, I will post the results when the new relay comes in.

Tom M'Guinn

Hmmm, based on how the flywheel sensors are used inside the DME/KLR, I can't really see how you'd get tach bounce without power to the DME/KLR. The tach bounce comes from the KLR and the KLR produces it based on ignition pulses generated by the DME's processor. Curious that you'd have tach bounce and a dead boost gauge. To save yourself the wait, you can try bypassing the DME relay. Search here for lots of threads on how to do that. Assuming that doesn't help, you might also think about bypassing the KLR and alarm (if equipped) and checking the ignition switch.

How do you know the coil is good, did you force it to spark?

Have you checked to see if you're getting fuel in the cylinders? You can pull a plug and smell/see if after cranking if the injectors are firing.

mhpd31

Well, it was not the DME relay, just put a new one in and no luck. I am definitely getting fuel, in fact after I finally get spark I am concerned about the plugs and the oil with cranking on it so much. I am pretty sure the car has an alarm, although I never used it and there is no relay plugged into it. I definitely still have tach bounce but nothing on the boost gauge. So is my next step to go after the alarm, or should I start thinking about the DME, I have rogues M tune chips in there now, I still have the factory chip and my old Lindsey racing chip, but I cant remember if either of those are compatible with the mass air flow sensor, got rid of the old air vane years ago..... thanks to everyone for the suggestions so far, slowly but surely tracking down the possibilities.....

mhpd31

Also, battery, oil and gas gauges come up when the key comes on. Boost and temp do not move.

mhpd31

Well, I just bypassed the KLR and it started up on the first turn and purred like a kitten. So now, how do I figure out if is the chip or the board? Also, the boost gauge still did not move?

Tom M'Guinn

Half glass full, but at least you isolated the problem. That's half the battle or more. The fact that the boost gauge is dead and the ignition is not making it through the box suggests it's not an isolated issue inside the box, but rather something preventing it from doing anything (e.g., bad chip, no power, fried processor, etc.). The boost gauge signal is generated inside the KLR and the ignition pulse passes through the KLR. I'd start by taking the KLR out of the car and check very closely for cracked solder joints. They can crack anywhere but are most common on the 25 big solder pads where the main 25-pin connector is attached to the board. Google for generic cracked solder joint examples if you're not familiar with how they look. If any look suspect, it's ideal to remove the old solder (cheap solder sucker works) and use fresh solder, but you can get away with just remelting the solder that's there if needed. I'd also remove the EPROM chip and run a pink eraser gently over the pins to remove any oxidization. If the KLR is still dead after that, then I'd try a new chip first, and lastly a new or rebuild KLR. ECU doctors in Florida will rebuild yours and/or swap it for a freshly rebuilt one. I may be able to scrounge up a stock KLR chip or image for you if helpful, and am happy to look at the box for you, but if you have the budget then ECU Docs is fast, painless and guaranteed to get it right...