3.0 Xantia misfire

David Goddard · Post by **David Goddard** » 05 May 2004, 02:49

When you did your spark plugs, did you fully reconnect the wires to the MAP sensor on the back of the inlet manifold? That could be the problem area, it's not sensing the manifold vacuum properly so the advance/retard may not be working. Usually most noticable under acceleration.

Stempy · Post by **Stempy** » 05 May 2004, 04:34

Yes, I checked and triple checked the connector, along with all other connectors. Like you, my thoughts are leaning towards the MAP sensor or the crank speed sensor, I'll have to connect up a meter and check the readings against the info you sent me. I have checked the TPS which appears ok and also the engine and air temp sensors seem ok.
I've also noticed that there is a particular flat spot at 1200rpm, and if you brake to a stop and then pull away sharply it will hesitate before picking up. I'm hoping Richards analyser may give some definite answers with fault codes, but I know the codes can sometimes be misleading or a code may not even register, though I think his device monitors various inputs in real time.