any ideas out there on duratec misfires.already changed plugs,leads and coil pack.oil is 5w30 ford spec.mis fires upto 2400 revs then seems to clear.does not happen all the time,just most of the time.any ideas wecome before the big hammer comes out.
MAF?
Disconnect the MAF, if it runs better with it off then it'll need cleaning or replacing. This may or may not trigger then engine management light which may or may not clear after a long drive.
This may be a bit simple but have you checked that the air filter is not now an air blocker?
had rac out with his diagnostic machine,checked everything but showed no faults.maf tested ok and lamda reading was fine.any more ideas?
It will have a Duratec engine, not a Zetec.