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vauxdoc, Other
Category: Vauxhall
Satisfied Customers: 1192
Experience:  Vauxhall diagnostic technician
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I have a corsa twinport with p0300 random misfires, and normally

Customer Question

I have a corsa twinport with p0300 random misfires, and normally 301 and 304, to match, had and tried everything, coil pack, plugs, swaped injectors, sump off to check oil starvation, inlet off to check twinport gates, its had an egr due to a intake leak its had a 2nd hand ecu, did 29 miles after fitting the ecu fine but normally 4 miles and it drops to 3 or even 2 cylinders, im beat.
Submitted: 2 years ago.
Category: Vauxhall
Expert:  vauxdoc replied 2 years ago.
Welcome to Just answer,

As long as you are using quality parts I can dismiss the things you have replaced as I have come across loads of dodgy after market coil packs.

Other common causes I have had are water in the petrol tank this can be seen settled in the swirl pot in the tank.

I have also had a few Corsa's with badly worn valve guides, as they move on the seat they can cause compression loss, this does not show up on a compression test, the head would have to come off.

I hope this helps, best regards,Customer