help with injector pulse

[Cannonball996]

I have an 83 944 and my fuel injectors are not firing, I am getting spark, in fact I can get the engine to run on starting fluid. I pulled the injectors out and tested them directly off the battery, and they fired and sprayed just fine, so I am sure its not an injector issue. next I tested the electrical wires going to the injectors, each injector was the same story, were both wires going to the injector were putting off a constant 12v. is this how it should be? if not then how should it work.

I also have a new DME relay in it.

[kfray]

The 4 fuel injectors have 12 VDC supplied to one pin and the DME Computer output pin 15 and 14 pulse to ground on the second fuel injector pin.
I would check the speed and reference sensors.
http://www.clarks-garage.com/pdf-manual/ign-02.pdf
If Sensors check OK the check the DME computer:
http://www.clarks-garage.com/pdf-manual/dme-01.pdf
http://www.clarks-garage.com/pdf-manual/dme-02.pdf
Once the DME computer is open check for bad solder joints

[Cannonball996]

so the hot wire pulses to ground to create a circuit to fire the injector?

[North Coast Cab]

Yes

[idontknow]

Originally Posted by Cannonball996

so the hot wire pulses to ground to create a circuit to fire the injector?

The injectors are fed with constant hot +12. Ground is pulsed on and off to fire the injectors.

[kfray]

Originally Posted by Cannonball996

so the hot wire pulses to ground to create a circuit to fire the injector?

One pin of the injectors are supplied 12VDC, the 12VDC is connected to a coil inside the injector, other side of the coil is connect to the second pin of the injectors and is pulsed to ground by the DME Computer.

[Cannonball996]

so both wires are suppose to be 12v, and the computer pulses one of them to ground?

[kfray]

Originally Posted by Cannonball996

so both wires are suppose to be 12v, and the computer pulses one of them to ground?

Yes

[Cannonball996]

sounds good, thanks for the help