2001 5.7 GSI stalls on throttle up.

[Campwinkler]

My 2001 Monterey 262 Cruiser with a VP 5.7 GSI PEFS, EFI-TBI will only run about 10-12 MPH at 3000 RPM. Only under load, driveway test all are good. If you try to push the throttle more, the engine slows and almost stalls. I have replaced everything !..... all ignition components, all sensors, new fuel pumps. and even exhaust risers and manifolds. My compression is showing low, so I have tried running several bottles of Techron to help with the valves. And it's a little better. Also ran the Seafoam into the TBI while running to maybe help with sticky rings. So, yesterday I ran it on our lake for two hours with the Techron and new gas. No joy, it just doesn't have the power to get up on plane.

 

[alldodge]

What are your compression numbers?

Is The fuel pressure between 50 and 60 psi?

 

[cobalt1999]

This is a TBI setup, Fuel pressure is lower....9 psi low side and 30 psi high side I believe.