Citroen XM Forum

blockage in the air intake or exhaust?

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Many thanks Dean and there is definitely no blockage/restriction in the exhaust from the fumes omitted! I did also detach the air filter hose that had no effect at all. With regards, Matthew T.

Must be a sensor issue then

There is nothing showing on the diagnostics or dash Dean but I shall persevere! I guess the lambda is the most obvious one to replace first? Regards, Matthew T.

Timing? Surely not.

i would think it would run a little lumpy if the timing was out rather than just being breathless.

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Timing? Surely not.

It is definitely not the timing Chris as the engine ticks over beautifully and just 'flattens' a little at high revs, while the issue has only just arisen! The engine was rebuilt before the last refit and pulled like a train with no hesitation at all, plus I am sure it is mixture related due to the slightly sooty plugs. I now wonder whether the flywheel sensor may have sustained some damage with the loose starter ring, that appears to have finished off the starter! The head of the sensor did look a little scraped and I shall swap with another spare. Regards, Matthew T.

If the crank sensor was damaged the engine wouldn't run.

That is a good point Will and I am now thinking more likely a faulty coolant temperature sensor, which does after all directly effect the mixture! With regards, Matthew T.

yes, if there is no EML light on it must be something variable the ecu would not see as a fault, like MAP, coolant or AF sensor, easy enough to check the resistance of the coolant sensor or swap with a spare.

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