99 jimmy idle

[Jc1500]

I have a 99 jimmy replaced rotary button, cap, plugs, wires. The truck doesn't seem to run right. It idles fine but when in load it starts to sputter a bit. Going down the road between 2000 and 2500 rpms the tach jumps a bit. Now if I put it to the floor the truck runs out fine.

[jamesslcx]

Jc1500, Check engine light on? Have you changed the fuel filter? Run fuel system cleaner through it regularly?

[Jc1500]

I just changed the fuel filter and put another egr valve on off another motor. I am about to try swapping the maf sensor then I guess its gonna be up to vaccum lines. The check engine light is on it is code 0452 and 0463. I am thinking I have a ground off somewhere from my recent install.

[old_master]

P0452 is indicating a problem in the fuel tank pressure sensor circuit.
P0463 is indicating a problem in the fuel level sensor circuit.
The ground for each sensor goes to a ground splice pack. One wire from the splice pack grounds to the frame, left rear corner, top side. Might be worth checking that first.