Sick of no-start issue. New reference senders on the way.
 

I've swapped out the dme, the dme relay, the coil. Bypassed the factory alarm, and still no start. My reference sender plugs look terrible anyways, so I just ordered new reference senders and just the plugs for the dme side. I had no tach bounce at all, but I've seen conflicting opinions on whether this means anything.

Wish me luck.

on the right path with getting new speed n reference sensors. I've had a no tach bounce a few times after getting new sensors, and it turned out my power wire (white) for the starter wasn't making a good connection at the battery.
Remember the front sensors, think its the ref. sensor, has to have a .8mm gap (-/+ .1mm) from the flywheel. But you shouldn't have any problems unless you messed with the sensor bracket

Luck wished. If you go from a hard cold start to a warm cold start issue after replacing the cross reference sensors, see if you have a leaky fuel injector. I was having a random hard warm start issue intermittently and ever since I replaced a leaky fuel injector it has disappeared.

Did you clean ALL of your grounds before you throw any more cash at it? I had a no-start issue this winter and was about to buy the sensors as well. Cleaned everything up, wiped some oil residue off the starter housing, and she fired right up.
The weird thing was the contacts really didn't look bad in the first place.

Didn't consider th grounds & starter. Gonna check it out.

Installed new reference senders and it fired right up! Took maybe 15 minutes. A note for the good of the thread, mine were mighty dirty, and I wonder if just cleaning them would have solved the problem. They must be magnetic, because there was some fine metal sticking to them. Cleaning them should be part of the troubleshooting process.

You left your 944 too long while you were doing your 911 resto:D:D,how is it going?have been following it from the early stages.
Good to hear you are running again ,did you use 944 sensors or the BMW ones?