i have my car dyno'd and its baseline was 250 hp with haltech e6k and we started to play with the fuel and only shiffting at 6500rpms because as soon as you co over 6500rpm my walbro started to drop the fuel pressure and by 7000 rpm the car started to lean out to 13's air fuel so but the most hp we got was 280 at 6500 rpm and my tuner told me that if my walbro didn't stop pumping fuel we could of gotten about 340 to the wheels so time to buy a pump and wheels

what you guys think about that

 

Is the fuel pump getting a constant >12v?

 

The walbro should hold ALOT more power than 280whp. Unless there is a problem with it your problem is not the fuel pump. Look elsewhere first.

Daniel