So I have a fuel starvation problem at full throttle. I was going to replace the fuel pump with a higher GPH, but the replacement pump with a higher GPH has the exact part number as the one I have. I’ve checked fuel lines pick up. everything is clear, switched carbs, still having fuel starvation problems. Other than an electric pump, what are my options. Summit racing has the Carter 4871 rated at 120 GPH. The unit I have on my vehicle, is rated at 45 GPH. With the exact same part number. Any idea why it would be this way? Any and all help is appreciated. Thank you.

 

Remove the fuel filter from the Quadrajet inlet. My car would start breaking up at about 4200rpm at WOT, found the issue was the filter. Removed it and ran fine. If that helps, get a filter without the check valve.

 

Make sure your float level and accelerator pump are set correctly before chasing your tail on replacing a fuel pump.

 

If your pump has a fuel return, restrict it. That worked for me.

 

I'm running one of those pumps on a 455. I like it but I can tell you it's pushing a LOT more than 7psi. I had to add a regulator to restrict it down to ~6.5. It was 8+ out of the box.

 

Why not troubleshoot before firing the parts cannon?
Whats the idle pump pressure to the carb? Should be 5 ± 0.5 PSI.
Pull the rubber end off the inline filter at the carb.
I chased the nose over starvation problem for years.
I think it's the only thing that saved the 400 from blowing up in my youth...built in rev limiter.
No more nose over.
Change that filter regularly.

 

Yes, the first place to start is by establishing baseline PSI as it sits. Should be no lower than 4.5.

If you confirm that the fuel pump supplies adequate pressure, the next place to go is inlet fuel filter as suggested above.