Non starting car

[DaveD]

Started fine on Saturday afternoon ..drove to the shops half a mile away and it refused to start...turned over fine... and when the recovery man sprayed quick start in the manifold and it fired (briefly)
So today tried a new fuel pump ...no joy had the auto electrician out to check the immobilisers ..no probs there and also the fuel pump is getting power so its not the relay...checked there are no loose plugs underneath the manifold ....where to from here ..before I get it towed in

[daimlerman]

Crank position sensor?

[DaveD]

would that stop it getting fuel?

[daimlerman]

If you are not getting fuel;
1 Fuse 11
2 Fuel pump relay,remove relay and link the green/violet and red/white wires...this should make the pump run regardless of ign switch.If the pump does not run,either the pump is buggered or the wire to the pump is broken.

If you are getting fuel;
Are you getting a spark?

Remove a spark plug and re-connect it's lead and lay it on the rocker cover,spin the engine over and watch for spark.

No spark?

Suspect CPR.
Suspect DME relay.

[Andyboy]

sprayed quick start in the manifold and it fired (briefly)

So it has a spark, of sorts. Sounds like the injectors aren't being triggered - check for power at terminals 16 and 17 on the ECU. It's very unlikely that the ECU has failed, but a possibility. Trying another ECU and DME relay is a plan. Doesn't have to be a 325i one - a 320i ECU will do.

It could also be corrosion in the multi plug under the manifold. There is a round screw connector where the injector wiring loom connects to the main engine loom. Twist the connector apart and look for green nastiness, and clean it up with WD40. I'm failrly confident that's the problem - seen it before a few times. It should be unscrewed yearly and dosed with proper terminal protector.

[Brianmoooore]

WHAT ENGINE AND AGE??

[Grrrmachine]

If this is Dave's cabrio, it's a 1992 325i Cabrio

[DaveD]

had the electrics (and the immobilizer) checked so I took off the fuel line to the fpr and it was dry and nothing when I cranked it over so I will start again from the fuel pump and check for blockages

let you know

thanks all

[Brianmoooore]

A quote from another thread I've replied to this morning: "Hot wire the fuel pump, so that you know for certain it's getting power at all times, leave the rear seat cushion off so that you can hear the pump clearly, and see if it is still running after the car dies."

[DaveD]

Will try that ..be on it tomorrow morning

[Green]

A combination of a bad relay connection and corroded multiplug wires caused this headache multiple times.

[DaveD]

right ....hot wired the fuel pump and ran it for a few seconds then tried to start the engine which turned over nicely then died ..so it seems to me to be the fuel pump relay as the fuse is ok ...which one is it and has anyone got any idea of the number ...I think it might be the middle one under the plastic cover on the nearside of the engine bay..

[Brianmoooore]

What's the fuel pump relay and fuse got to do with anything if the pump's hot wired?

[DaveD]

Because it establishes that the fuel pump works ..there are no blockages and as the fuse is ok that only leaves the relay that could be at fault ...or can you think of anything else

[Brianmoooore]

You are supposed to be running the engine with the pump permanently hot wired. This is a) to eliminate all the pump control circuit from the problem for the time being, and b), to see if the pump runs (by the sound it makes) whether the engine is running or not.

[DaveD]

tomorrow

[daimlerman]

If you are not getting fuel;
1 Fuse 11
2 Fuel pump relay,remove relay and link the green/violet and red/white wires...this should make the pump run regardless of ign switch.If the pump does not run,either the pump is buggered or the wire to the pump is broken.

Come on Dave,you can do better than this!