engine runs rough

[98torch]

i got off early today and decided to change my oil. everything ran fine but i went to the automatic car wash cause i didn't have time to detail my truck and when i left the engine started to stutter between 8 and about 1500 rpm but it only did it in drive, butnot park or neutral.

[PeterbiltChrome]

Do you mean the engine actually stuttered under the low acceleration? If so, that makes my story pretty irrelevant.

 

My dad's 98 pickup (5.7 vortec) did that after about a year, mostly when the a/c was on, idling in drive sitting still. The RPMs would bob up and down. I believe they flashed the computer with some new software because it was a computer screw-up. I think the comp was misinterpreting feedback from the transmission pressure and compensating with throttle. It didn't stutter, just bobbed up and down.

[budhayes3]

How old are your cap, rotor, wires? May have gotten a little moisture on them causing a misfire after the car wash.