83 944 no start

[piepoli]

Help. Until yesterday no problems with our 83 944. Now starter turns engine energetically, but no spark and as best I can tell, no power to fuel pump either. Checked fuses and pump relay, all OK. Everything else works. Car came with factory fender mounted alarm/anti theft. Unit now inside side panel and still connected, fender hole filled. Been this way for over a year and OK. Any ideas where to look for problem? Thanks...

[speedracing944]

Do you have a voltmeter to check to see if you have power going to the ignition coil?

Speedy

[blk924s]

have someone listen and put their hand on the pump while you crank the starter to verify that the pumps bad. It should hum pleasantly along.

[piepoli]

Should the pump come on with the key in the "on" position, or would I have to be cranking starter? I had no current with just the key "on" and not cranking. Thanks.....

[mjadair]

The pump runs while you are cranking, it doesn't do anything while the key is just on and the engine not running.

Have you checked the DME relay. My understanding that this is problematic.

[blk924s]

The key has to be turned to START for the pump to run, and it should also run for a couple of seconds after the key is released, assuming your car doesn't start.

[piepoli]

Thanks....Doing this solo so I pulled the Fuel Pump and while off the car ran leads to the battery......it runs fast and smooth. So, I can take that off the list. When taking it off the outlet fuel line did not drain a drop back....so it was dead dry. Obviously no power to the pump. Next stop?

[piepoli]

To check power to coil, I assume there should be power at the two terminals when the ignition is in "on" position, or would it have to be cranking the starter? Thanks. I have already tested the fuel pump after pulling it from the car, and it runs smoothly with direct 12 volt input. Thank for your input.

[mr. dude]

I would check the speed and reference sensors. This was the culprit in the case of my car with the same symptoms.

[piepoli]

The speed and reference sensors, are they under the hood on the back/top of the engine next to the firewall, or are they on the transmission below the car. I've seen them referenced before but never had a clear idea of their whereabouts. Thanks....

[piepoli]

When I turn the key to start there is a click (I assume from the DME) followed immediately by a click in the fuel relay. I had my fingers on it for certainty. So, they seem to be OK. I will be checking the reference and speed sensors once I locate them. Thanks for your input.

[onZedge]

Since you are working solo, attach a voltmeter to the two fuel pump terminals of the factory wiring and position the meter so you can see it from the driver's seat. See if you have power to the pump while cranking.

With the ignition switch turned on, you should have power at the coil terminal black wire. Power to the coil comes directly from the ignition switch.

With the ignition switch turned on, you should have power at all the fuel injector terminal red/blue wires. Power to the injectors comes directly from the DME/Fuel pump relay.

BTW, the DME computer does not click - there are no relays in it. The DME/Fuel Pump relay is two relays in one module.

Do these things FIRST before going on to the reference/speed sensors. Report back and we'll go from there.

[CT944]

When cranking the car, if the tach does not bounce slightly, it is the DME unit itself. Try giving your DME a few whacks in between cranking, as sometimes it is a solder joint that is not making complete contact. DME is right above the pedals, under the dash.

If you have a friend who has an early 944, you can try their DME. It only takes 2 minutes to swap.

The same issue happened to me, after replacing all of the sensors, relays, wires, cap, rotor (about $500 if I remember correctly), it was the DME. I bought a used one off E-Bay for $50 and it started right up.

[piepoli]

Thank you SO much. I won't be able to get back to the car until Saturday, but your tips are sure to help.

[piepoli]

OK. Fuel pump is fine. Good power to fuel pump leads when engine is cranked to start, so I reinstalled fuel pump. Coil: With ignition on there is current to the black lead on the coil. I pulled a plug and NO SPARK, also pulled coil wire from distr. cap and no spark. Pulled electrical plugs from sensors located at top rear of intake and interior contacts were clean and dry. Going to pull the coil and run to parts store to check. Am I missing anything? Sounds like I have elliminated possibility of DME/Fuel Pump relay as I have current and I can feel and hear the relay engage. Any suggestions beyond the coil?? I appreciate your help. Thanks again.

[Britwrench]

If it turns over quicker than normal , then maybe the timing belt broke?
You won't get a spark if the cam (and therefore the rotor arm) isn't turning.

Make sure the DME is new, they should be changed to the later 993 part number.

[nynor]

if the timing belt is broken, the engine will spin over and sound, more or less, like a sewing machine.

[piepoli]

Thanks, but it is cranking at the normal speed and sounds the same as usual. I just pulled the coil and tested it at .8 - 1.0 ohms. I have another Bosch Blue Coil that tests 3.6 but I can't find spec anywhere to compare. I also do not know if the blue coil is compatible with stock 83'.

It appears that possibly whatever device should trigger a spark at the coil is not doing its job, or the coil is bad. Where would I trace down the "trigger" device? DME? Thanks guys.....

[nynor]

there are sensors at the back of the engine, on the bellhousing, that pick up a signal from the flywheel.

[piepoli]

I took a look at the 2 sensors, damn they will be tough to get at if that's the problem. I checked the two connections they feed atop the engine/rear and they were clean and dry. Is there a test procedure to check the sensors that are so hard to get at? THanks