Brady B

2002 4.2L V6, 5 speed manual tran, runs smooth when first cranked, then begins to idle roughly after sitting in neutral for a few minutes. I really have to accelerate when taking off in first gear, then smooth shifting ( enough gas) from there on out. I had a faulty fuel pump replaced after I got stranded in a parking lot about 4 months ago. Truck seems to run rough even after highway speeds, such as at a stop light after exiting the interstate. Any suggestions as to what this is or how to fix it?

fleetnuts

Might check the FPDM by the spare tire, make sure it's not corroded. I kind of had the same problem but it was my coil pack going out. For some reason I would always loose a cylinder. I replaced the pack with a Delphi coil pack and Taylor wires. Problem fixed. Mine is an 08 4.2 though, maybe this helps. Maybe someone with your year model will comment.

Brady B

Maybe someone with my year will post. I appreciate your efforts, I'll be sure to check it out.