wont run over 2000 rpms 2004 4.3 GXI-e

[Cruisers2880]

HI ,
From spring launch port engine wont run over 2000 rpms , it backfires, and wont take any throttle. Changed plugs wires, cap, rotor still the same, Fuel pump has constant 50lbs of pressure. Swapped fuel regulator, coil with starboard engine didn't change. 170 lbs. of compression per cylinder. No DTCs, timing is ok. No idea???

 

[dubs283]

Probably time to investigate fuel supply to the pump(s). Anti siphon valve/pick up tube, fuel line condition, filters, etc...

 

[alldodge]

I would replace the distributor cap. While it may not be the problem the flat caps are known to go out without warning. So much so it's recommend to keep a spare on board