common point?

[aerokurt]

hi all, 83 944, been sitting 2 years, CRANKS OVER fine[fresh battery, good compression] but no spark and no fuel pumping. was running when parked. am i missing some dumb single point to check out? kurt

[overkill]

Ummm, dead battery? The gas in your car if there is any will probably be stale as all hell you might want to replace it. You should change all your fluids before you start the car. 2 years is along time!

[Mike B]

Have you checked the fuel pump fuse and the DME relay...The relay tends to stop for no apparent reason...Try removing it and gently tapping it...Sometimes that works or just pick up another...They are $15-$20...

Other than that perhaps your fuel pump went south...

[SoCal Driver]

Originally posted by aerokurt
hi all, 83 944, been sitting 2 years, CRANKS OVER fine[fresh battery, good compression] but no spark and no fuel pumping. was running when parked. am i missing some dumb single point to check out? kurt

Check for battery voltage at the coil. If so then the ignition switch is good.

No voltage at the injectors (with the key on) means your DME relay is not working.

You could pull the relay and remove the plastic cover and clean the contacts with alcohol and 600 grit wet/dry sand paper. A couple of passes with the sand paper then swab with the alcohol. Don't over do it.

You may want to check if the contacts are pulling in by putting 12 volts across the coils. With the relay open and on a bench ground pin 85 and put plus 12 to pin 86. This should pull in the fist set of contacts. These power the DME and the injectors -- pins 30 to 87. To check the secondary contacts (these run the fuel pump) ground pint 85b and put 12 volts to pin 87. This closes 30 to 87b.

You can also test the fuel pump with the DME relay removed by jumpering from socket 30 to socket 87 then turn the key on. This should run the fuel pump. If not check the fuse #6 on the "extra" or no cover fuse block. In fact it would be a good idea to give all the fuses a bit of a twist to knock off any corrosion that may have occurred in two years.

The fuel pump gets a short run from the DME when the starter is engaged. After that the DME has to see the signal from the speed sensor to keep the fuel pump running -- contacts closed.

Should the DME relay test out and work then you check the AFS and the speed sensor.

The AFS (Air Flow Sensor) might be stuck. Have to remove the filter and using a wood dowel reach in and press on the vane/door to see that it moves. You can check for voltage at the plug and that the resistor inside the AFS is working by pulling back the weather boot on the AFS plug. Also seen where a squirrel and got into the air filter and make a nest.

The speed sensor is the back most of the two. This should give 2 volts when cranking the car.

The reference sensor tells the DME to fire the sparking bolts. This signal is better seen with an oscilloscope but you can use a diode and a resistor in series to check it.

You do want to freshen the gas. Drain the tank and put some fresh gas in it.

Once you have it running change the timing and counter balance belts. In fact I would do that now before it starts running.