Rev Issues

[BrokenCupholder]

New owner and user here. Forgive me if this has been discussed already, I can't seem to find much info on it. Please direct me to any existing threads or info on this if it has been beat to death.

I picked up an 02 XLT 5.4L 4x4 yesterday. Bone stock as far as I know. Under consistent throttle and from ~1800-~3500 rpms I notice very inconsistent power output. Every second or so revs will jump up 100-200 and then back down 100-200. Idle is not perfectly stable, but the issue does not seem to present at lower rpms. The tach does reflect the change in rpms. Exhaust smells unusual, though this is probably entirely unrelated. The issue is perfectly liveable, I just dont want to be doing any damage by driving it.

I am driving almost exclusively at altitudes of 7100+ ft above sea level, if this makes any difference. Its about 50 degrees F here. Low octane fuel, and as far as I know, 5W-20.

Thanks for any help guys.

 

[CARO'S98EB]

IF your expy came from a lower altitude ti may need to adjust to the altitude[barometric pressure]. you can speed this up by doing several WOTs [wide open throttle] while driving. the computer adjusts the baro only at WOT.

 

[BrokenCupholder]

Thanks. Ill give it a shot, see if the problem persists.

 

[maverick]

New owner and user here. Forgive me if this has been discussed already, I can't seem to find much info on it. Please direct me to any existing threads or info on this if it has been beat to death.

I picked up an 02 XLT 5.4L 4x4 yesterday. Bone stock as far as I know. Under consistent throttle and from ~1800-~3500 rpms I notice very inconsistent power output. Every second or so revs will jump up 100-200 and then back down 100-200. Idle is not perfectly stable, but the issue does not seem to present at lower rpms. The tach does reflect the change in rpms. Exhaust smells unusual, though this is probably entirely unrelated. The issue is perfectly liveable, I just dont want to be doing any damage by driving it.

I am driving almost exclusively at altitudes of 7100+ ft above sea level, if this makes any difference. Its about 50 degrees F here. Low octane fuel, and as far as I know, 5W-20.

Thanks for any help guys.

The IAC (Idle Air Control Valve) may be ready for a change or cleaning. Mine idled very high also until I changed it to a new one. The altitiude may affect it too, but I would not think it would that much.