Falls flat under acceleration

[BILL NIVEN]

1990 Silverado K1500 5.7 automatic. Under normal acceleration the truck runs good. Pull out to pass accelerating from 50 mph it has no power and spark knocks pretty bad. You can feel passing gear kick it but will not accelerate.
I have a new TBI, IAC, fuel pump and filter, plugs, wires, ICM, cap and rotor, converter and rebuilt trans. I have replaced every sensor under the hood but no change. Verified initial timing at 0 degrees with computer disabled. Fuel pressure checks normal at idle, had to add Schrader valve.
I have a new distributor but not installed yet.
I am a shade tree wrench Turner and its obvious I have missed something. Any suggestions would be appreciated. I prefer to do my own work and not take to shop.

 

[skylark]

What is your fuel pressure when it falls on its face?

 

[DerekTheGreat]

Also, is the check engine light being set when it knocks? The previous engine I had in my '89 would do that, I suspect the knock sensor or wire going to it had issues. I'd dip into the gas pedal, it would knock real bad for about a second and then the CEL would pop on & timing advance was disabled- code 43. No timing advance makes for a pretty lethargic engine.. I didn't mess with it as it started doing that a week before I had the engine swapped out for one which ran on all 8. This 'new' 8 cylinder doesn't have that issue.

 

[BILL NIVEN]

I need to verify fuel pressure under load, at idle its 12 psi with Schrader valve mounted in line coming out of fuel filter.
No check engine light when starts knocking under acceleration.

 

[PlayingWithTBI]

1990 Silverado K1500 5.7 automatic. Under normal acceleration the truck runs good. Pull out to pass accelerating from 50 mph it has no power and spark knocks pretty bad. You can feel passing gear kick it but will not accelerate.
I have a new TBI, IAC, fuel pump and filter, plugs, wires, ICM, cap and rotor, converter and rebuilt trans. I have replaced every sensor under the hood but no change. Verified initial timing at 0 degrees with computer disabled. Fuel pressure checks normal at idle, had to add Schrader valve.
I have a new distributor but not installed yet.
I am a shade tree wrench Turner and its obvious I have missed something. Any suggestions would be appreciated. I prefer to do my own work and not take to shop.

You have 2 threads going on this - don't know why?

 

[BILL NIVEN]

You have 2 threads going on this - don't know why?

My mistake will delete