Misfire

[Fitzy2011]

I,m currently on Fraser Island with a badly misfiring 4.6 Gems. It seems like 2-3 cylinders but not all the time, but lasts long enough to be a real problem on soft sand.
I have removed and emptied the fuel filter which was spotless, checked all leads etc, it has not got remotely hot, so I,m really in need of some suggestions please.

I,m thinking fuel, but Rainbow beach is very busy so their fuel would be renewed constantly.
Any help really appreciated.

[bee utey]

Remove all the plug leads one by one, check for loose boots or burnt connections, polish the coil post insulation, use cable ties to tighten the boots on the coils, check the coil low voltage connection plugs aren't loose or corroded. Remember each coil does 2 cylinders at once.

[Fitzy2011]

Thanks for that. I didn,t realize the coils were like that, so that could be the issue. I,ll have a look when I come back from fishing.

[Rupert Prior]

2 and 3 are on the same coil, so act as a pair (pull the plug lead off one and both will shut down) could possibly a bad 12v supply under the coil pack at that coil, (but there are loads of other possibilities)

[Fitzy2011]

thanks for the help guys, but it seems to be running ok now. I didn,t find anything wrong, but did fill it up with 60 ltr so maybe (hopefully) it was bad fuel.

thanks again.

[benji]

That's just rude! It's cold and wet down here, and your slacking it on Fraser....:p But,oh man that brings back some memories. We stayed at a mates place in Urangin the night before we caught the barge; the stupid thing wouldn't run for more than a few minutes, coughing and spluttering. Next day, and all the way home it ran fine.

We were very low in the tank, and I think i've got some crud it was sucking up.

Have you gone up the Ngkala rocks? I hope it's better than when we were there. Had to go down to 8 psi, had to use a lot of power to get back.

Have fun.

[Fitzy2011]

Yes mate at Ngkala yesterday but still very tough stuff. I don't mind rubbing it in, Fraser is just one of those magic places, and if you like 4wd,s it's even better. Not much happening on the fish side of things, but we tend to drown our sorrows quite frequently and prepare for the next days assault.
The seas are huge today so the beach will be interesting from now on.

I,m glad you enjoyed your trip here.

[Fitzy2011]

I came back from Fraser with the Rangie still occasionally misfiring, but when it does it can be very rough. I changed all the plugs, leads are only 8ks old, changed all the coil pack, and it purrs for a while then starts again. There are no errors on the obd2 tester I have. I have removed the fuel filter and visually checked it and it was very clean, as it was replaces 8k ago also. I have checked as many electrical connections as I can find, and it doesn,t seem to have any specific reasoning behind it, under load not under load, at idle sometimes, not other times.

Now I,m stumped! Any suggestions would be great.

[Vern]

crank angle sensor?

[Fitzy2011]

Ok, I,m not familiar with the crank angle sensor, would it cause that sort of problem, and where is it located please.

[Fitzy2011]

I have found where it is thanks. I'm going to change the fuel filter first, then the crank angle sensor and then who know's. MAF ???

[RR P38]

Have you had any water spilled/or entered the cab around the front seats?(BECM).
Water in the in the ECM under the battery compartment would be my first look see.

[Fitzy2011]

No water at all. I haven't done the crank sensor yet as I,m still not convinced, but if it persists I,ll have to keep eliminating things, but thanks for your suggestion.