5.0 has engine miss

[cabits]

Seems that at low engine speeds like under 2500 rpm that the engine has a miss every once in a while. It can happen several times in one minute up to not any misses in many minutes. I was thinking the fuel pump but it has 39 psi. at the rail. Plugs were changed as well as the cap and rotor and fuel fliter. It also does it when I take it out of overdrive so its not the tranny lockup. Any ideas?

[Rex Havok]

Originally Posted by cabits

Seems that at low engine speeds like under 2500 rpm that the engine has a miss every once in a while. It can happen several times in one minute up to not any misses in many minutes. I was thinking the fuel pump but it has 39 psi. at the rail. Plugs were changed as well as the cap and rotor and fuel fliter. It also does it when I take it out of overdrive so its not the tranny lockup. Any ideas?

I'm not real sure about the fiveO but I have a 4.6 and the plug sits about 5 inches down into the head, the factory wires have a plastic insulator that I found on mine to be sparking thru and off the engine block. It was a lucky find because of how small the burn hole was, I was on the road and the miss kept getting worse so I used some cheap black tape and it smoothed right out. I purschased a new set of wires that are all rubber and have not had a problem, I would check all that first and look real close at the inside of the rotor, if it has one. That's really all I can say without being in front of the car ya know. This is just my experience. It stumped a few ppl who looked at the insulator. What was Ford thinking anyway? Good luck Rex

[peppermrj]

I'm with Rex, plug wires. Look at night and or mist it down with a spray bottle of water to find the offending culprit.