306 XSi Engine behaving oddly... - Lsr
Late '97, 306 XSi 2.0 16v:

In July after a 100 mile trip, my engine died and the engine warning lamp came on. It restarted OK and warning went away.

Over the next few weeks the problem started happening more frequently. Pug dealer said it needed new plugs, HT leads and coil pack. I changed all of these (except no HT leads, the coil pack sits on the plugs directly) but the problem persisted and it's happening more often.

A reliable way to bring the problem about is to hoof it over 5000 rpm for a sprint. After a few seconds, the engine loses power, then often cuts back in, then maybe the warning light comes on for a few seconds goes off. Throttle can become jerky, like an on/off switch.

When it's in this mood and I put it in neutral and take my foot off the throttle normally the engine sinks below idle and dies. Sometimes the ECU revs the car repeatedly and the revs bounce and sometimes it recovers and idles normally.

I've just taken it to an independent garage, he cleaned the stepper, changed the fuel filter and refitted the plugs and coil pack. It was fine! the problem appeared to have been fixed, I could boot it no trouble but...

25 miles later it's back, engine lost power completely, warning lamp on, the complete show.

Fuel problem? ignition problem? or something more fundamental like a head gasket?

any ideas please?
306 XSi Engine behaving oddly... - the conductor
this may help but a lot of pugs with sagem or marelli injection suffer from probs like these. normally the coil fails and causes irepreable damage to the ecu. you can tell this due to fault codes in the ecu's fault memory which cannot be cleared. i know on 106 1.1/1.4's the coil has been replaced with a modified part to solve the interfrence probs which wreck the ecu. i would take the ecu to an atp electronics dealer for a check. costs approx £25.
306 XSi Engine behaving oddly... - IanT
It's odd that when the mechanic "cleaned the stepper, changed the fuel filter and refitted the plugs and coil pack" things were OK for a bit, even if only for 25 miles. It makes it likely that one of these items is on its last legs - and the stepper is the one which is most likely to cause your symptoms.

See www.honestjohn.co.uk/forum/post/index.htm?v=i&t=87...9

It's not quite the same description as your problem, but similar enough to be possible.

306 XSi Engine behaving oddly... - Lsr
Thanks for replying, it is odd that it behaved itself for the time it was with the garage, but not beyond chance. I agree that if it is anything he did then the stepper seems the most likely candidate but can a stepper motor fault affect anything other than idle speed?

It's unlikely to be two separate faults as the stalling always occurs after a jumpy loss of power during accelaration - they're not independent problems.

Someone else has suggested a faulty oxygen sensor, could this produce these symptoms?


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