944 Starting Problems - DME or Sensor?

[Corse]

Ok my 83 35k mile 944 is just cranking but will not fire up. I have just changed the DME/Fuel Pump relay with a new unit but it didn't cure it. It ran perfectly only 5 days ago. After checking its service history I noticed it had the same symptoms in 2005 and the garage changed the DME relay but also the Rev. Impluse Sensor #944-606-115-00 . Is there a way to check this sensor? If this is not the culprit could it be the computer itself? any guidance will be greatly appreciated.

[Dave L]

When I got my car the car wouldnt start sometimes, it would just crank and crank but never catch. I put in a new DME relay, the ingition was replaced buy the PO and the starter was replaced by the PO. Turns out it was a cracked solenoid on the starter.

[running_cold924]

does it have fuel??? check the rail

[many944s]

At the top/rear of the engine, behind the intake manifold there are the connectors for the speed and reference sensors. (these will be in a bracket stacked vertically) Alot of times these connectors get corrosion on the pins, which cause loss of spark. Disconnect each connector and plug them back together making sure you don't swap the connectors, as then it definitely wont start! In my experiences this fixes a no-spark issue about %50 of the time!

Hope it helps!
-Nick

[Corse]

Originally Posted by running_cold924

does it have fuel??? check the rail

I'll check...should the pump should still have pressure on just cranking even if the sensor or DME itself is out? even so my gut feeling is steering me towards the crank sensor...I had the same thing happen to my Triumph motorcycle, replaced it and it ran. The difference was that I had a ton of spares to pull from to perform a process of elimination...not so for the 944!

[Corse]

Thanks for all the help...it was the connectors behind the manifold!