Vauxhall Zafira missfire

[ngc84]

Any help would be appreciated thanks.
I have a 2002 1.8 petrol automatic zafira, it came up with some warning lights and was very sluggish, (emissions and traction control lights). They cleared after turning the car off and on a few times, but then came back on a few days later and won't clear. Took it for a diagnoses and was told it was a misfire on cylinder 2 and would be the coil pack. Since then i have put injector cleaner additive through, filled with oil, changed the spark plugs and put a new coil pack on but still have the miss fire. It runs ok first thing in the morning with the lights on but after half an hour or so starts miss firing again.

Any suggestions what to do next or what the problem might be?

 

[Belle427]

That's a strange one any ideas of the codes that were read?

 

[ngc84]

it was just miss fire on cylinder 2 and one about the immobolizer which cleared.

 

[stuartturbo]

Top gasket leaking is the common one but since you done that.
try searching the dodgy ecus on the 1.8 remember them on the rear off the engine block failing but cannot remember how the faults manifest themselfs

 

[Burnerman]

If you keep the lights on, does the problem not occur?
John

 

[ngc84]

Yes it runs fine for a while (did about 30 miles yesterday before it happened) with the warning lights on but then when the car gets warm it starts missfiring.

Tried a different coil pack again just in case and still no good but might need to reset.

It doesn't seem to have an egr valve unless it is well hidden.

Also the mass air flow filter and sensor seem immaculate and look virtualy brand new.

As for the ecu i was trying to leave that til the very end as its pretty expensive, and not sure if i want to spend that much on it.

 

[Astra99]

My son's 16v Astra had a similar problem. The codes indicated that there was a misfire on cylinder 3, and true enough, plug 3 was sooty. It turned out, after replacing the coil pack to no avail, that the REAL problem was the air intake temperature sensor. Replacing this cured the problem.

 

[ngc84]

The sensor looks brand new and even disconnected the lights are there, but i might try taking it off and leaving it off or trying one from a breakers, the plugs i took out where all still white and didn't look burned up at all but i replaced them anyway.

I'm starting to think its the injectors but struggling to get a price for them, i just get told bring it down and we'll plug it in by the places i have phoned.


Thanks

 

[Belle427]

coolant temperature sensor is the main culprit when a car performs ok cold but plays up as soon as the temperature rises.