mbsibar

Hi all,
I had no issues with my 1985 944 until I decided to replace the oil temperature sensor. I also took the air intake off for cosmetic work.
I thought nothing could go wrong with this but the engine didn't start after I put everything back.
It sounds like the engine fires all 4 cylinders but doesn't even try to idle.

there are a few things that I already checked.

* DME - Tried 2 new DME relays
* Fuel Pump - Rail Pressure
* Ignition
* Vacuum line connections

There is a video of the issue

Gage

Where did you find an oil temp sensor to replace?
Check or wiggle the connection for the speed sensor (DG).

mbsibar

Sorry, water coolant temperature not oil.
I checked the speed sensor, looks brand new. But I'll wiggle and see if it does the trick.

931guru

Classic large vacuum leak. Look for a missing large vacuum hose at the bottom of the air intake manifold.

walfreyydo

Agree on vacuum leak. There also may be a line that connects to the underside of the intake - so check that as well. Another possibility is that since there are TWO coolant temp sensors on these cars (one for the gauge and one for the DME) that you may have accidently replaced with the wrong part.

Carrera51

Running into a similar issue trying to get the 5 years dormant 86 NA my son got from his uncle. Replaced fuel pump, both the crank and speed reference sensors. Car came with two DMEs which we tested in a running car and both worked. Also replaced the DME relay. When I crank it, it turns over and tries to run, but backfires and sputters. Already turned the engine by hand and it does turn freely.

Gage

OP,
Does your fuel gauge work?

walfreyydo

Vacuum leak, timing or fuel issue. Put a fuel gauge on the rail and evaluate, double check plug wires/correct firing order, confirm injectors are firing. These are the things I would check first
http://www.clarks-garage.com/shop-manual/ts-01.htm

BeerBurner

Stupid question, but did you plug the air flow meter back in?

I replaced my voltage regulator over the weekend and my car did the exact same thing when I tried to start it. Oh yeah... I forgot to plug the AFM back in. It works now.

BB.

mbsibar

You are a star


Found the missing connection. it's quite difficult to see the connection underside of the intake.
I haven't tested it yet, once the rain is over I'll connect and see if it works.

Thanks a lot for all your replies.
I'll update you.

mbsibar

The engine is running better than before now.

Thanks a lot