98 c1500 4.3 vortec misfire

[Menard09]

Truck idles fine but misses on acceleration, doesn’t matter if it’s p/n/d. if I unplug the tps it runs mint. It has a solid 5v signal and good ground. 3rd wire goes from 0.5 volts to 4.5 volts with no hiccups. Truck has a new fuel pump and spider injector. New plugs and wires. New maf and tps

 

[1997]

check engine light come on? codes? vacuum ok? fuel pressure good? quality wires/cap/plugs? double checked everything you did?

sounds like its time to plug in that scanner or get one.

 

[Menard09]

No codes. Fuel pressure is 62 when pumping then holds at 53/54psi. Plugs are ngk platinum and wires are a Napa mileage plus. Scanner plugged in and maf reads 2.42 g/s with the engine off. Short term fuel trims stay around -7 when in a closed loop. Long term I’ll have to check again.