Unique Xantia XUDT that thinks its a P/T direct injection!

[Sturdybloke]

Hey all,

I've noticed a strange thing with the new car. Sometimes when the engine is hot it wont always start straight away. It will churn over for 4-5 seconds and then start. When the engine is turning over the rev counter needle will quickly and only once flick up to 1200 rpm and then when the engine starts it reads 0 and the engine sounds like a direct injection - Noisy.

I noticed it the other day and when it happens the car is down on power. Switch the engine off and start it again and it's fine - nice smooth engine and a working revcounter. I get the feeling that it has something to do with the pickup sensor for the revcounter needs cleaning or replacing. Ive read through the archives and the posts with dodgy revcounters have no mention of noisy engines Anybody else ever come across this before? All pointers, hints or tips welcome

Many thanks in advance.


P.S over 750 miles covered in it so far

[CitroJim]

Hi Craig,

You're right on the diagnosis Either your needle lift sensor (on No.3 injector) or your TDC sensor (on the top of the bellhousing) is playing up.

Both have a role to play in driving the tacho which is, in turn, driven from the ECU. Disconnect each sensor in turn and you'll get the noisy engine sound as the ECU failsafes to "limp home" mode.

You may also see the engine managememt light illuminate.

The needle lift sensor is favourite but before condemming it, break apart the connectors on each sensor and give them a good clean.

[Sturdybloke]

Thanks Jim. I have a few hours to spare today so I will give the connecting terminals a good clean.