I've been chasing a misfire all over the place.

1st I had a misfire in two cylinders, 6 & 4 maybe??? I replaced the plugs and wires and that fixed it. 5k later it was back. 4 and 5. The electrode on plug 4 was completely gone, so I replaced it along with the plug wire. Nothing was wrong with cyl 5, so I put that back in. Again, everything worked fine.

Now, my misfire came back. It had been misfiring when cold and all the way until you had been driving it for over an hour. Now it has cured itself. I had the code read...misfire cyl 2.

Any ideas?

EDIT: 97 f150 4.6L...yeah, I searched already

 

Were the wires old? They could be rubbing somewhere, causing premature failure.

 

I wasted allot of time chasing ignition probs , not no more - I usually end with the same fix any way. If I were you I find a good deal on eBay and replace the coil packs at the same time - that you know everything is firing the same on each cylinder.


Good Luck

 

Wires are brand new.

Jbrew, I think I might end up doing that. Or at least swapping them to see if the misfire moves.

Also, I have had a pretty bad knock for a while now. Any way these problems could be related?


Thanks guys.

 

Hey, I went down the same path. Miss seemed to disappear and then would reappear.

Part of the early diagnostic process was to test the coil's primary and secondary resistance. Both were in spec so I spent a lot of money and time in replacing stuff.

After doing all the possible fixes, I thought what the heck and bought one new coil tower to see if this would help. As luck would have it, I guessed right and replaced the right one and the truck has been running great ever since.

good luck.

aloha,

ihilani