5.7 Vortec In Bread Truck Engine Boggs Under Acc.

[pna]

I have a 02 gruman olson with a 5.7 vortec. 80% of the time, the engine will start to rev. up, then boggs. Sounds just like a clogged convertor, not enough fuel supply, or not getting enough air. All three have been verified, 60psi fuel psi, both 02's removed, gauge installed, no back psi, cleaned and checked mass air, replaced air filter. checked for any air restrictions. Then at times, engine will rev. and drive fine. only had 300 code which could be anything. All parameters within spec according to the modis. Any suggestions?

[Mike G]

First off, welcome aboard.

 

Secondly, what type of ignition system is that running. If it's the old cap and rotor, check into that family next.

--Mike

[Draenor]

Does it seem to stall under load at WOT or slight throttle? If at WOT or close to it, replace the fuel filter.

[pna]

complete tune up performed new cap, wires, plugs, map sensor, rotor, fuel filter. No ecessive play in dist., it only boggs at wot. Half pedal, engine is smooth. Does not appear to be skipping at all, just will not rev up past half throttle, just the typical bahhhhh sound at wot