454 losing power under load

[phathead]

"I have twin fuel injected 454

"I have twin fuel injected 454's throttle bodies that are fwc and sound awesome while idleing. As I power up they still sound and are running great. The problem starts when I am running at 2800rpms for 15 min the motors bog down to 1500rpms and then shoot back up to 2800. This issue continues ad there is a general loss of power from the motors.
I changed the fuel filter, which I have three per motor and have cut them open and they are clean. The tanks are older (1969) and are steel, but wiht out any contaminates in the filter I have a hard time believeing it is the fuel....

Any advice?"

 

[justintime]

run a sea-foam treatment
migh

run a sea-foam treatment
might be clogged injectors

 

[agladney]

"Hey, had the exact same probl

"Hey, had the exact same problem myself with my 322 Silverton 6 months ago. Replaced fuel filters etc, but it persisted. Finally someone told me about this weird little fuel screen, it is inside this small (3-4 inches diameter, 1 inch thick) frying pan looking thing, right next to where the fuel line goes into the engine. The screen was totally groady, cleaned it and voila, no more problem! no cost, and easy to do, though a little messy disconnecting the fuel line... Let me know if this is your fix!
B^)"