2000 4.0 help

[cllake]

Check engine light is on, saying misfire in cylinder 5, it also said cylinder 6 one time. It seems to be random with 5, never constant.

I checked all the plugs/wires and their fine. Could it be 5's injector? What do you guys think? What should I try?

I just bougt the truck and it wont pass emissions like this..

 

[Earl43P]

I would suspect a plug wire, spark plug or coilpack LONG before I suspected an injector.

 

[cllake]

By coil pack do you mean distribution block? I pulled every wire while the truck was running and it has spark going to everything cylinder. The plugs/wires seem fine but Im going to buy the single wire to that cylinder to see if it helps. Other then that I think its an injector but I am by no means a mechanic.. Help me out guys!

 

[Beanmachine7000]

I'd start by giving it a good tune-up, plugs and wires and see if it still does it...

 

[cllake]

I just flushed the cooling system, engine changed all fluids and filters. I guess ill try the plugs and wires also. My buddy owns an amsoil shop and he suggested his fuel injector cleaner so im going to run a full tank of premium with the additive and see what happens.

 

[vaderj]

i just put a can of bg 44k in a full take of 100% gas (almost everyone up here sells 10% eth.) last night and my motor already seems to be running a little snappier; it could of corse just be my imagination but I think I am getting a little better millage already (50 miles and im not to the 3/4 tank mark yet!). that $hit is pretty spendy though, one shop wanted $25 for an 11oz bottle, but I found it a can at an exhaust shop for 12$ ea.

 

[Toms01PSD]

By coil pack do you mean distribution block? I pulled every wire while the truck was running and it has spark going to everything cylinder. The plugs/wires seem fine but Im going to buy the single wire to that cylinder to see if it helps. Other then that I think its an injector but I am by no means a mechanic.. Help me out guys!

If you're going to replace one, replace them all. It's like changing brake pads, you don't just replace one side, you replace both. Check your spark plugs, they made need replacing.

 

[jasonl]

Is there any chance someone changed wires and crossed #5 & #6 ? Or are they original wires? How many miles on it? The coil pack is one solid unit. If you have a water spray bottle you can start the truck and spray a fine mist of water over the wires and in a semi dark area you will see spark jumping if they are shorting out.

 

[cllake]

I checked and the wires aren't crossed, and they aren't original. It has 112,6XX. I have to wait to get paid then I will buy all new plugs/wires and If that doesnt help ill move to the injectors. Should I replace the coil pack before then?

 

[Beanmachine7000]

Yeah, I would...