When it idles it missfires.

dont know what it is.

injector light is on.

While it's dark open the bonnet and look for blue sparks when you start the engine up! If you see any there's your problem, if not report back

bredsticz said:

While it's dark open the bonnet and look for blue sparks when you start the engine up! If you see any there's your problem, if not report back

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why would there be blue sparks. And where abouts should i look?

Along the HT leads, it shows sparks if the wires are damaged or not connecting well with the coil packs or spark plugs, Most common cause for misfire

bredsticz said:

Along the HT leads, it shows sparks if the wires are damaged or not connecting well with the coil packs or spark plugs, Most common cause for misfire

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think its headgasket

Why what symptoms you having? No hot air from heaters? white smoke from exhaust? Running rough? Oil in coolant? Losing oil/coolant?

bredsticz said:

Why what symptoms you having? No hot air from heaters? white smoke from exhaust? Running rough? Oil in coolant? Losing oil/coolant?

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It runs very ruff. header tank bubbles, hot air from heaters still works, no white smoke, cant see in coolant to confirm that oil is in there.

Hmm, the heater is usually one of the first things to go when a head gasket does, although other things make it sound like that. Do a compression test and that will confirm it