Fuel System woes any advice ?

[TeGriffic]

Took the Griff for a blast this afternoon and lost power and then the engine completely. The fuel pump isn't priming and looks like it has died.
Now, the AA man says that the injectors are not operating and the inertia switch isn't either. I noted a few weeks ago that the pump was whining a little. Is the injector and inertia switch failure normal if the fuel pump fails to operate (ie. do the injectors operate without the fuel pump. Am I looking only at a failed fuel pump or something more major (or minor such as a fuse) ?

And if you were the red Cerb down by Southend Airport about 6pm that came past me twice, nice exhausts. I was the green Griffith waiting for the AA to take me home.

Any advice, as always, much appreciated.

[spend]

Check the relays (and their connections) and fuses in the ECU "bundle".

Dave

[catretriever]

numpty question...but is there any way to check a relay other than just swapping it out?

[griffter]

catretriever said:

numpty question...but is there any way to check a relay other than just swapping it out?

You can physically connect the terminals that the relay would connect - but you better make very sure you connect the right ones! Look to the relay layout for a clue - and most relays have a helpful circuit diagram on the relay body. You also need to check the circuit which should switch the relay, with a voltmeter or similar.

Back to original topic, check also the ECU connector itself.

>> Edited by griffter on Monday 25th October 12:48

[GreenV8S]

There are several ways for the supply to the pump to fail, and you can eliminate all of these by applying 12v directly to the pump. None of these affect the injectors though, that is controlled purely by the ECU. The only things I can think of that would take out the fuel pump AND the ECU are:

block connector between the ignition switch and the main loom

fuse

main power relay (one of the two metal cased Bosch connectors on flying leads by the main fuse box).

The relays can be tested electrically if you have a basic understanding of electrics, otherwise test by substitution.

[spend]

Check with multimeter against the wiring diagram.

Clean the contacts and test with standard relay (dont use for long time tho - it will flatten battery)

Test relay by connecting up primary circuit and listen for click and/or multimeter across secondary circuit.

Dave

[red griff 500]

If you definitely know that your fuel pump is not working because you can't hear it when you first switch on the ignition, then I would say that it's 99% sure that the problem lies somewhere between your ignition switch and the pump itself - I don't believe that faulty injectors can stop the pump working.

Jack the car up (make sure you prop it with axle stands or similar) and see if you've got 12v at the pump connections with the ignition on. If not,then find the fuel pump relay (in my 500 it's a metal bodied bosch relay in the loom - unfortunately there are two identical relays but I don't know what the other one is for) and check that as the previous guy said.

Hope this helps.

Steve

[tegriffic]

Thanks for the replies. A mechanic on the phone today ventured it may be the immobiliser playing up.