Citroen XM 1996 VSX Turbo Auto. cranks but does not start

[Keith10]

Hi All
I have the above car which has been stood for some years and just got around to bringing it back to life. The problem is the car now cranks but will not start. I have been investigating the electrics and particularly the action of the double relay which in my case is housed in the ECU box. I have tested the relay out of the car with a 12 volt supply to Relay1 80 ohms / Relay 2 81 Ohms in turn and they seem to be operating OK with firm click no chattering and contacts are making OK with 0.8 ohms as per multi-meter reading.
The following symptoms have been observed with the relay mounted in the car:-

1) The initial priming cycle to the fuel pump is not functioning when the ignition is ON and proven as there is no voltage appearing across pins 1 and 2 at the fuel pump. The fuel gauge is working and fresh premium fuel E5 in the tank. I cannot hear any click of the relays when ignition is turned on.

2) Pin 12 of the relay is spare as I understand it should be for this version manufacture date 02/02/1996 (I have heard the re was a version change very close to this date).

3) The internal commons of the relays Pins seem to be OK ie: Pins 4,5,6.13 / Pins 1 and 9 / Relay 2 Pins 2+ve to 3 via diode and Pins 14 +ve to 12 via diode. each showing 745 and 756 ohms respectively.

4) Whether the ECU is kicking in and also the camshaft position sensor which tells the ECU that it is cranking I cannot tell at the moment.

5) there is no spark at the plugs during cranking.

Given the above observations I would appreciate assistance if has anyone got any further tests I can perform to narrow down the problem further. Thankyou

[xantia_v6]

The fuel pump priming when the ignition is switched on should be the first problem to chase. It is controlled by the ECU, so check that the ECU is sending a pulse to the fuel pump relay.
It is not unknown for the ECU output to fail, but check that the ECU is receiving 12V on all of the pins that it should.