98 Ranger 3.0 misses at 3000

[ajames942]

Sorry to post this in the general discussion but no one has answered my other threads in the 3.0 section. The problem is the truck idles good, and when you rev it it dosn't miss....but when its under load like on flat or uphill it misses at 3000 and anything below 3000 or above 3000 it runs beautiful. I don't understand what the problem can be....if it helps I just replaced the 1998 3.0 engine that was blown with a 1999 ranger 3.0.

 

[AllanD]

a miss at the torque peak rpm is usually an ignition problem.

Plugs, wires or coil pack.


Good idle makes me suspect worn plugs or excessive gap.

AD

 

[straycat]

Man, my 99 Ranger wit 68,000 miles on it was doing the rough idle and the jumping/pulling/jerking feeling earlier this year. It was driving me crazy. I added some fuel cleaner to it and filled up the tank. Drove it for about 10 mins. and it seemed fine. The next day it started it again. I could not figure it out. Under hard exceleration it started to pull fine and then it fell flat on it's face when I came to a stop light. I yanked a plug wire loose and no diff. Same rough idle. So I tried the coil wires and no diff. It must only be at a certain idle I thought, so I took it to my Goodyear shop and paid the $90.00 to run the diagnostics on it. #4 plug was fouled. I had them put in all new plugs in it sine they had it apart and it has been running fine since. That was $50.00 for the plugs and install. I never thought it was a fouled plug. I put in new wires last week.