944 No start

[Leander]

Hey everyone thanks ahead of time.

Bought my project 1987 944. got it to start after some electrical.
After electrical I wanted to make sure it could idle safely so I changed timing belt and oil cooler gasket.
Turn the key after it’s all done and nothing but crank. What?! I rotated the engine well after timing belt and all the marks lined up.
After some tinkering the fuel rail started making a high frequency whine like a VCR when power was applied I’m not an electrical guy any ideas?

My troubleshooting was disconnecting the fuel rail connectors and seeing which created the whine I believe 1-3 created some sort of noise.

[usury]

Let me start with an obvious question. Are you certain the engine is at top dead center when the mark on the cam gear lines up? The cam rotates at 2x crank speed, so the mark on the cam gear also lines up twice per engine revolution. Only one of those times is TDC. (Interference wise, I don't know if the 944 engine tolerates the cam being 180° out of phase, so maybe it isn't that.)

Since the distributor cap had to come off to do the timing belt, is it possible the plug wires got hooked up wrong? Is the rotor installed in the distributor cap? Coil connected to the distributor? Power at the ignition coil?

I'm just running through my own mental checklist.

[Leander]

Yea I ran through those checks too, it was TDC I checked the flywheel for the marks. As for the spark it should have not changed since start, cables go from cap to correct plug.

[usury]

Hmmm, let's see what else is on my "crank no start" mental checklist...

Fuel in the car? Vacuum lines at the fuel pressure regulator and damper? (As an aside, make certain you replace the rubber fuel lines that route over the exhaust header. Several places sell kits.)

DME/fuel pump relay? Connector and wiring at the crank position sensor?

[Tom]

High pitched whine is unusual. I'd be inclined to pull the connectors off the injectors to see if that goes away. If so, I'd suspect frayed wires inside the injector connectors. You can try rattling the wires too to see if they creates any sign of life while cranking.

Does the motor pop and sputter while cranking (suggesting cam timing issues) or just nothing (suggesting no spark and/or no fuel).

Does the tach bounce (twitch) while cranking?

How's the DME relay?

Beyond that, I'd check for spark at the #1 plug lead (put something metal in there and place it close to the intake while cranking to see if it's sparking). And then check for fuel by pulling a spark plug after cranking and smelling for gas.

[Leander]

Thanks Tom, the whine was my biggest worry with that put to bed I can get onto other tinkering I’ll get to work with some of your advice.

Paul

[Tom]

Thanks Tom, the whine was my biggest worry with that put to bed I can get onto other tinkering I’ll get to work with some of your advice.

Paul

Not sure I understand. Did removing the electrical connectors from the injectors eliminate the whine?

[Leander]

Thanks Tom, the whine was my biggest worry with that put to bed I can get onto other tinkering I’ll get to work with some of your advice.

Paul

Not sure I understand. Did removing the electrical connectors from the injectors eliminate the whine?

Yes, see my original post, cyl 1-3 connectors I tested in sequence with only one connected and they each made either a whine or a hum. Cyl 4 made no noise I’ll look into those connectors

[ROB III]

THANK YOU-THANK YOU-THANK YOU
In my case its an 89 Turbo that was just fine last Saturday, but went to start today and it just cranked.
Thanks to a search here, reading Usury and Tom's short list to Leander's request for help, I suddenly remembered I bought a couple DME relays as spares on advice when I bought my car in 04.
Found them buried in my tool box, swapped out the DME relay and VOILA...SHE SINGS like an Aria from a German Opera (well, almost, its been brisk here and the throats a little verklempt)!
Did some searching on RL for additional background and education due to the years of posts there as I recalled several, and one fairly recent one was a rather extensive process by pins, relays, crank sensors, signal repairs, FT9 DME swap with no positive result (good view of how complicated it can get though).
I had visions of bad harnesses, sensors, cracked DME solder joints, all things far beyond my meager skills, spiraling into oblivion, but a simple DME relay switch was all it needed. I tend to fear the worst and hope for the best, and got lucky....this time!