Hello all, I am new to this forum and I am in need of help. I have a 1997 f150 with the 4.6l and I got a code cylinder #5 misfire, I changed plugs and coil pack. Took care of the problem for two weeks. Yesterday I got the same code. So why would I get the code again and what would cause it? Is there something I am overlooking? Any help is greatly appreciated, thank you.

 

Did you change the plug wires?

 

Not yet, just got new plugs and wires today. Going to change them and coil pack tomorrow

 

Switch the coil pack to another cyl and see if the misfire changes. If not then you have deeper issues. If so, buy new coil pack

 

The coil packs seldom go bad - but wires and plugs sure do.

I hope you got MOTORCRAFT plugs and wires, these engines don't like aftermarket. Torque the plugs to 28 ft/lb and use dielectric grease.

Sarge, that engine has 2 coil packs, each handling 4 cylinders. You are thinking COP (coil on plug) which are *not* "coil packs".

 

Thought it had 8 like my vette lol. That's how we would figure out a bad one on them.

Carry on, I was never here

 

Could it be a bad injector causing the misfire code?

 

Are there 8? If so change it to a different cylinder and see if the code follows it

 

Yes

 

FWIW the number 5 plug is right next to the thermostat housing/elbow. Check for moisture you may have a leaky o-ring that might not show up until under pressure.