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Hi Folks, this is my first post, so please show a little mercy on me for starting a new thread on a topic that has been beaten to absolute death, however...
I have a late 85 N/A 944 that's been sitting for 15yrs. She ran when I had to park her during the arrival of my son (baby seat+sports car=nope). Fast forward to present... I'm trying to resurrect my "first baby" but have the most persistent no-start condition I have ever encountered in my entire pathetic history of turning wrenches. The car will turn over like a champ but Just. Won't. Fire. Lest you judge, here's what I've done so far:
- Read every related forum post, Pelican DIY, Clark's Garage article, random internet posting, Haynes manual, bootleg service manual, watched countless YouTube videos of varying reliability and downloaded / printed about a thousand pages of info for reference.
- Drained the old rotten gas, flushed the fuel lines and fuel rail, replaced the fuel pump, fuel filter, weird bendy fuel pump hose, fuel pump relay and injectors.
- Replaced the infamous Reference/Speed sensors (TWICE! I initially bought the FAE brand, then read some not-so-nice reviews and bought the Bosch ones - neither caused her to fire up, but I now have slight tach bounce, which I did not before replacing.
- Replaced the infamous Reference/Speed sensor wiring and ran it directly into the DME plug after the OEM harness literally fell apart in my hands as I tried to strip it back to tie in a new plug (the old plug had also disintegrated in my hands).
- Tested the new infamous Reference/Speed sensors for resistance both at the sensor and at the DME plug - both good. Then I bought an oscilloscope and tested the AC signals - both good.
- Checked signal to injectors with noid light (all good) and I can smell gas at the tailpipe when I turn it over several rotations.
- Replaced the coil, plugs, distributor cap & rotor.
- Cleaned all of the ground sites I could find until they sparkle (Yes, they were rotten) Two on the bell housing, two pairs under the dash on the driver's side (Ask me how fun that was. Let me add that I DON'T LIKE SPIDERS), one pair in the hatch, one cluster near the drivers side headlight, one cluster (in the pit of hell) near the passenger headlight (I ALSO DON'T LIKE WASPS).
- Cleaned up the alarm bypass that I did years ago.
- Opened the DME unit, no obvious problems, circuit boards surprisingly clean, but could probably use a re-solder?
Now here's where I'm stumped:
- Checked spark coming out of the coil with a spark tester. I get a single flash when I turn the switch on, then another single flash when the starter engages. Then no more spark from the coil... What. The. Crap. ??? What kind of output should I expect to see from the coil and what would cause that to not happen other than the DME, which is, I'm afraid, my next, expensive step.
I also have a flickering condition in the dash lights (all of them except the low fuel light) that did not clear up even after cleaning the grounds. They will go on/off randomly when the ignition switch is on.
My gut is still screaming "Ground!! It's a bad ground/bad connection somedamnwhere..." but I have yet to find it. Is there another ground that I've missed? Could it be the ignition switch? Is the DME the only other thing that could cause this b***ard not to run? Anybody? Bueller?
For the sake of my sanity and what is left of my hair, can someone please tell what I am doing wrong here? (Besides the obvious trying to resurrect a 15yr dormant 944 that's full of wasps and spiders...)
Yep, I kept a spare relay in the fuse box, but bought a "fresh" one and installed it when I replaced the fuel pump -also tried the "bypass" method at the fuse box just to be sure. Good point on the belts - I'm sadly familiar with zero valve clearance on these cars. Had to get the head reworked many moons ago when she was still my daily driver after ignoring a "faint whining" noise. I stayed on top of the belt maintenance after that .
follow the clark's garage procedure to remove the ignition switch and jumper the contacts to see if you can start the car.
could be your "start" position is good but your "on" position is bad.
Soooo, after much gnashing of teeth and exhausting of all other known options, I re-opened my DME unit and took a much closer look after reading a few posts having to do with roasted resistors and the transistor that makes the coil work (won't even try to reiterate -see links below and OMG thank you to the guys who posted them!!). I think I may finally be on to something. Can't believe I didn't see it the first time I looked, but there is definitely a dark spot under R518 & R528. I ordered a transistor and a couple of new resistors tonight - will update the results once I get them installed. Wow, I hope this works... not sure the board is viable under that shadow, or if my soldering skills are worthy, but I guess I'm getting ready to find out!
02-26-2018, 07:34 PM
1985.5 N/A 944 Epic No-start
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