Vauxall cavalier misfire

Where in the rev range does the misfire occur? Is it violent?

The misfire occurs around 2-3000 rev and is very violent almost like its backfiring.It mkes the whole car jault.

no misfire - you need a new catalytic convertor. current one is blocked.

Which is likely to be bollocks.

I'd check the coil myself.

If its a really aggressive misfire or infact a momentary total cut of the engine, i'd be looking at the coil and/or HT leads back-feeding the ECU and causing it to momentarily shut down.

Tim..

"pete" wrote

I doubt it, but if it is, then a piece of scaffold bar is quite good at cleaning them out.

Wife's Renault Magane did this, turned out to be a split vacuum hose to a mixture sensor. Replaced it (about £3.50) and all is well.

It seems the vacuum pipe goes to the engine map (so I've been told) and when it's split the vacuum varies between a normal mixture and one higher than choke, hence backfiring and a reallly serious feeling of juddering. First time we felt it it felt like a rear wheel or the whole axle had dropped off.

Put a match to it.

Like most have said, it's 99% an HT issue (spark). A weak spark can be 'blown out' easily, and this is more noticable at higher revs with increased air flow.

This is a distributor engine, so replace the coil. It's pretty much standard across the Phase II Vauxhall (1.6 - 2.0 8 valve) engines. You can steal one from any 1.6+ Astra, Calibra, Cavalier, Carlton etc etc. Don't take one from a 1.0/2/4 engine as they are different coils.

P.S I presume you replaced the king lead (the lead from the coil -> dizzy when you replaced the leads?).

I have replaced the coil,ignition module,engine position sensor and this has made no difference.I have removed and tested the MAP sensor and this seems ok.When looking in the top of the fuel injection unit wjth th car running it seems like there is a lot of fuel sitting on the throttle plate.Could this be being caused by a faulty lamba sensor?