I have a 1990 C 1500 with lq4 swap I have 42 pounds injectors and a 255 pump it seems that anything under a half a tank if I floor it from a stop it will start surging. can I be sucking the fuel bucket dry

 

I had the same problem with my lq4 back when it was stock, it was the fuel pump. The lower the gas tank, the worse it got.

 

Btw i still had the factory pump and bucket when it happen to me.

 

Could be, yep.

 

Very possible. A lot of guys including me cut the bottom out of the bucket and sit the fuel filter on the bottom of the tank. That way there is no chance of the bucket getting sucked dry. With mine like this I can get pretty low without issues except on really hard launches. Less than a 1/4 tank.

 

Thank I will pull pump and look may just go ahead and install 450 pump and cut up bucket. It seems to get worst as it gets lower. Thanks

 

I would guess that your fuel pump pickup is not properly seated "in the bucket" or you have alot of crud floating around in the fuel tank obstructing the flow. Either way you should drop the tank and see what's going on...don't just automatically start throwing new parts at it.

 

i find it to be a huge pain in the *** to get your fuel pump out, so i would just change the pump and filter while its out. the walbo 255 is only around $100

 

It already has a 255 pump thats less than 6months old. I didn't find it a pain to pull the pump I just lift the bed off less than an hr start to finish.

 

I lifted the bed off too, i found it to be easy but a pain. Btw I had a 255 pump die after only about 8 months.