P0303, p0000

[Fraser1989]

Hey guys,

I am working on my truck and am starting to research what I need to in order to fix the misfiring. I have P0303 and 4 codes of P0000. So I have a misfire in cyl 3 and random misfire.

I have read up on the probable causes and they seem to be plugs, coils, a valve sticking or a cracked head.

The truck only seems to misfire while at idle so I am assuming it is most probable that it is a spark issue? It is a 4.0 OHV with 260xxx KM on it. What do you guys think is most likely the cause?

It drives really smooth and gets good gas mileage on the highway. I have average 19 mpg with the instant MPG on the scangauge going to 23mpg. So I am assuming that it is not likely the head but what do I really know anyways.

I have ran 2 cans of sea foam through the gas tank and 1/4th of a bottle in the engine oil for about 200km then changed the oil.

I run injector cleaner and gas line anti freeze every fill up too.

 

[adsm08]

Do plugs and wires, coil pack if it is really old too.

Postin' from teh Galaxy

 

[Fraser1989]

Ordered Plugs and wires.
Ill let you know how it goes.

 

[TwoTon]

Usually a set of plugs/wires will do it, I was running my 4.0 on four cylinders due to two bad wires but it seems odd that it only does so on idle... when I would hit highway speeds and my crappy AT would put it in overdrive, my truck would violently thrash due to the misfires. It also sounded like a cammed-out v8 at idle I'm hoping thats all you'll need to do, but it doesn't make sense that it "stops" misfiring after idle, at least to me