I have a 1992 F150 with a 5.0 that is missfiring when it shifts up to 4th gear (Auto) and is at low RPMs. If I kick it down and increase the RPMs it seems to clear up. I had a problem like this last year and replaced the coil and it cleared up. Any ideas?

Thanks for the help, Rayban33

 

Possibly some bad wires/spark plugs. When was the last time they were changed? If it is the plugs or wires, the coil didn't "fix" the situation, it just prolonged the inevitable. Maybe it put a little more power to the plugs and it fired ok for a little while until they wore even more.