944 Not Starting

[Dalto123]

Hi all,

Having a bit of an issue with the 944. Went out to start it up just now but won't fire up. Initially i thought that it may be the battery. But I don't think this us the case as the red light on the immobiliser was on (when the battery had been flat the light is out).

The engine turns over, but it isn't firing up. This is confusing me. If it matters it's an '89 S2 3.0, it's been serviced recently so all spark plugs etc are fresh. It's used quite regularly but not for a week or so.

My mechanical knowledge is basic at best best go easy on my could be a flat battery (I hope). This just seems odd as this hasn't happened before.

[pauljmcnulty]

Is it turning over very slowly? You need enough revs for the fuel system to be switched on.

DME relay is often the cause, cheap to replace and every 944 owner should carry a spare. Immobiliser problems are common, often have several badly-fitted systems on one car!

[Dalto123]

pauljmcnulty said:

Is it turning over very slowly? You need enough revs for the fuel system to be switched on.

DME relay is often the cause, cheap to replace and every 944 owner should carry a spare. Immobiliser problems are common, often have several badly-fitted
systems on one car!

I always use throttle on startup, however it had no effect whatsoever, will look into the immobiliser fault, have never experienced this before though. As for tuning over it goes at its 'normal' speed, nothing. Unusual.

Edited by Dalto123 on Friday 30th September 16:40

[Conian]

dme relay is much less of an issue by the time 968 came out but do check it

can you hear the fuel pump prime when you turn the key (but not so far to activate the starter motor)

[pauljmcnulty]

I'd suspect DME relay as the first place to look if you've not replaced it before. Worth buying one, as for about £20 you'll have a spare even if it's not faulty.

You can make up a DME relay bypass, see http://www.clarks-garage.com/ to find it, but it's easier just to buy one.

[rallycross]

As said DME relay (fuse box) common issue and easy to change try that first, my last 968 had that a couple of times, it happens intermitantly and without warning and can be a right pain until you get a new relay.

[HAB]

Also check fuel pump relay

[bertelli_1]

Conian said:

dme relay is much less of an issue by the time 968 came out but do check it

can you hear the fuel pump prime when you turn the key (but not so far to activate the starter motor)

fuel pump only activates during cranking on a 944.

OP - does the rev counter needle move while its cranking? If not its most likely an alarm issue (cutting power to the ecu) or crank sensor failure.

[Dalto123]

bertelli_1 said:

fuel pump only activates during cranking on a 944.

OP - does the rev counter needle move while its cranking? If not its most likely an alarm issue (cutting power to the
ecu) or crank sensor failure.

To be honest I didn't really look. I don't think the rev counter needle moved.

[Conian]

bertelli_1 said:

fuel pump only activates during cranking on a 944.

I have 2 of them and you can hear the fuel pumps prime as soon as the ignition is on

[GC8]

HAB said:

Also check fuel pump relay

The 'DME relay' is a combined ECU relay and fuel pump relay - two relays in one case. The first (ECU) relay is energised by the ignition switch and the second (fuel pump) relay is energised by the ECU whe the engine is cranking sufficiently quickly.