c5 hdi random stutter, momentary power loss, or stalling

[haydent]

So one thing fixed and another appears

I have this random stuttering problem like a misfire or the brakes being tapped while driving along not necessarily accelerating.

The RPM needle might drop momentarily, the speed limiter will disengage and the multifunction display will come up with the "seat belts not fastened" warning and return to the default screen from example the trip screen.

Not all of these will happen all the time, sometimes only the stutter, sometimes all of them and even sometimes complete power loss, where it wont start for a few minutes.

Sometimes it will stutter once within a 15 minute period, sometimes 2-3 times within 30 seconds.

Ive checked in Lexia and there seems to be no consistent error after the stutter if any. More varying ones as symptoms of the initial problem what ever that is.

[sparksie]

If this was a VAG product, I'd be saying ignition switch fault.
Unfortunately, I know nothing about the C5, so any advice I give will be general automotive, based on experience of conventional cars.
Something, somewhere, is cutting power to some/all of the ignition circuits, or perhaps just the ecu.
In any case, it seems likely you don't have an electronic fault, as such. You're "switching off" and "switching on", so the problem lies on the battery side of the ecu, which can only see the event (stop and restart) which could perfectly feasibly be initiated by the driver and therefore can't be considered a fault.
Look for bad connections, sticky relays, warm electrical components of the ignition switch (assuming the C5 has anything so old fashioned), loose main fuses, etc.
Don't forget to check the earth side of all suspect circuits, too.
It could even be a main body earth, if that's separate from the engine ground.
Sorry I can't be more specific, but my own Xantia is the only Citroen we get to see regularly. Hope the little I HAVE said helps in some way.

[haydent]

thanks for the suggestions, it may just be coincidence, but since cleaning the manifold air pressure and temperature sensors with maf cleaner it hasnt done it since... here's another thread similar: http://www.frenchcarforum.co.uk/forum/v ... =3&t=50635" onclick="window.open(this.href);return false;

[Peter.N.]

Check and clean your battery connections.

[haydent]

spoke too soon.... it did it again last night after nearly 2 weeks without doing it, funny thing is it was right after filling up from a servo we normally dont go to. Also i recently gave it a oil and filters change.