Citroen XM Forum

Typically the injection would be disabled by switching the control signal to the main injection relay, but they could have done something 'clever' like just cutting the feed to the injectors to keep the trip computer reading.

That is helpful information but do you know whereabouts on the car I might find evidence of such adjustments? Regards, Matthew T.

I had another brief session on the car earlier today trying other ignition coils and modules as before but still no joy! Any further suggestions? With thanks and regards, Matthew T.

Try disconnecting the petrol injection ecu for a good 20 mins to reset it.

Many thanks for that, although I have tried both disconnecting the ecu and fitting other ecus and the orginal also works fine on other cars! Regards, Matthew T.

only the very slightest splutter of ignition and no real firing

You seem to have explored all available options and my input here probably won't help either, but I could not help remembering issues I had with older cars in the past.

1. weak spark, faulty or shorting out leads to plugs or lead to distributor
2. engine flooding
3. spark timing totally off

You may already have done this, but I think I'd remove all the plugs, place them on the engine block and operate the starter.

Edit: Might it just be the TDC sensor?

Thanks for your comments Jan and I had another brief session on the car today to my great relief finally fixed the problem. I realised there was one electrical component I had not thoroughly checked namely the distributor rotor arm and after cleaning the inner central contact she started first time!!! I had cleaned contacts around the rotor outer edge and the distributor cap and centre carbon brush and I now feel a bit of a fool for missing something so obvious. Both the cap and rotor had been recently replaced, but the car had been little used by the previous owner, combined with the damp weather. Anyway another lesson learned and although a lot of time was spent at least I now know the condition of the wiring etc. and I tidied up many things along the way. Regards, Matthew T.

Excellent news Matthew. It's always the most obvious thing overlooked. Done it myself today with the door connectors and front windows not working. Never mind, you have it working again. Happy days!!

Here is a photo of the car as my original post was some time back! I hope to report further plans and other history I have secured in the near future. All being well she will make her debut at the CCC National Rally in July! Regards, Matthew T.

Excellent, look forward to that!!!