Citroen XM Forum

Many thanks for that Mike and I will try disconnecting the throttle sensor on another car and report back. With regards, Matthew T.

Hi Matthew

Have you checked the voltage output from the throttle position sensor.
The ECU only accepts the signal sent and sends the equivalent injected fuel.
No checks on the validity of the signal level and no EML because the ECU is happy.
So say that signal peaks at 2 volts instead of the 5 volts it should reach it will act like a limiter.
The V6 guide I posted leaves the TPS checks blank.
I only picked up on this by reading through the equivalent V6-24v document which list voltage tests.
Closed should read 0.1 to 0.5 volts, fully open 4.5 to 5.0 volts.
I think your idea of direct wiring the TPS signal has considerable merit.

John

Thanks for your comments John and I will check the throttle sensor output before I try the replacement wiring. I know that the sensor itself is good as it was taken from a working car, so if the problem is from this location then it has to be the wiring really. Although not mentioned before, I did replace some crimped connections in the throttle sensor wiring to the harness adjacent that looked a bit dodgey with soldered joints that unfortunately brought no change, but there may be others elsewhere! With regards, Matthew T.

I can now report that partly thanks to assistance from Dave I think I have found the problem with the engine and should know definitively later today. Does anyone want to guess the issue and as a clue neither a lack of fuel or electrical glitches are involved! Regards, Matthew T.

Hmmm...

ooh the suspense!
glad you sorted it Matthew!

D

Ahhh. Torture!

I think over the full length of this saga there has been a stab at every component of that car from the fuses to the nut holding the steering wheel, I think the only thing that's not been guessed at is the transmission and the chassis!

D

Furry animals & nests in the air filter....

Mat stuck under the accelerator pedal.........