Josh do you have a wiring harness for a NA 1988 944?

 

Injector Driver Transistors in the DME have a pass-through pin on the circuit board,= known intermittent cold solder joint. DIY is a bit skechy without a high power pencil iron, heat sinks, and a mag glass. '944Online' will do it for you in reasonable time and expense, they are a RL forum sponsor and a stand-up group of guys. [Ian, Steve and Jamie]

 

Ours did exactly this.
Reflowed solder joints on DME transistor / per archives, no change.

Inspected the two sensor connectors --- speed and reference.
One was crumbling.
Pieced the wires back together ---- bingo.

 

Still no luck injectors get power in run and start position the grounding pulse is what we are losing during startup. I have replaced the DME with a known good DME. Has anyone had problems with the ref sensor wires going to the DME? Still would like to know what is different as far as sig wise to the DME during startup. Noid light flashes while running but no flash during startup.

 

No - do not - sorry.

Your problem sure is a stumper. Should be related to DME/ignition switch/DME relay/Speed and Ref Sensor in yet it sounds like you've already covered those areas.

 

Check the 14 pin connector block that sits beside the brake booster, above the clutch master. Injector power goes through that via pin 2. Gently pull that apart and see if you have 12 volts on pin 2 with the key in start and run.

On the battery connections theres several thick red wires that get bolted to the battery in addition to the starter cable. Are all those connected tightly?

Have you tried a new/different battery or adding jump leads from a second battery? Is it cranking slow compared to the other car you got the DME from?