Hi guys it never ends here goes had a miss fire problem off and on plugged in icarsoft and it reads Avam shaft position timing over advanced or system performance bank 1 last occurrence minimum signal signal low. Persistent misfires drive cycle c . Cause last occurrence maximum signal. Cylinder 2 misfire cylinder 3 missfire .Have changed. Plugs and coils on both and it seems to run fine for a while until you push her and it starts misfiring again.any help would be realy appreciated

I had a never ending chase for misfires, plugs, coil packs etc....

Turned out in the end it was valve seat regression , if you can look at the inlet vacuum values to see if they are in range ?

Cheers Gavin not sure if icarsoft will do that will check later .Took num 3 plug out looked at it it looks fine changed ignition coil and she has ran 5 miles perfectly crazy stuff

Should add my rocker cover gasket is needing done got a bit of oil down plughole but I have dried it all out and it is still doing it

As it's an M62, the oil must be coming from one of the rubber washers under the valve cover bolts which are inside the area surrounded by the gasket. Ron B. VK2OTC
2003 L322 V8 Auto
2007 Yamaha XJR1300
Previous: 1983, 1986 RRC; 1995, 1996 P38A; 1995 Disco1; 1984 V8 County 110; Series IIA

Yes thanks or the gasket itself will get round to fixing it shortly

Ok so missfire still there intermittent what to do anyone ?

rik wrote:

Yes thanks or the gasket itself will get round to fixing it shortly

When you replaced coil packs did you replace the whole thing including the tubes or just the upper coil pack?
CATS. Blocking can give strange engine faults
Battery and alternator need to be tip top too

Hi holiday just changed coli packs whole thing with rubbers not new ones though but working ones once changed and faults cleared she runs for a few miles no prob then starts misfiring again .Can I change rubber grommet without cover removal?

Oh and battery and alternator are good

Another update.changed a couple of spark plugs and coils on cylinder 2 and 3 cleared fault and she ran a dream gave her a good push uphills with no sign of miss parked her up for 3 hours went to shop and the misfire is back with a vengeance EML flashing etc .What can it be people.if it was valves it would do it all the time surely.engine not making any rattles or undue noise pretty quiet.it seems that she don't like being driven cold .Any ideas going slowly mad .

Can you check faults again with your diagnostics, did you clear the previous faults ?
Injectors or injector wiring, have you had the injector loom box off for any reason?

Hi yes cleared all faults injectors box not disturbed going to have another go at it clean the maff clear faults check wiring etc don't understand why she will run ok until I switch her off and she cools down and restarts if I let her tick over on cold start for a while she seems to be better

Crankshaft sensor (intermittent)?

or

Fuel pump/s... .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

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