In my 86 D150 I just replaced the fuel pump. One of the old mechanical ones that mounts to the motor block. The old one was leaking really bad when I started the vehicle and would continue for 10-15 minutes afterwards. The new one fixed the leaking problem, however; now the truck has almost no acceleration. It kind of lugs a little bit. I know it’s not a race truck and I shouldn’t anticipate it ever being so, but it has killed my truck once or twice trying to launch from a dead stop. I put some fuel system cleaner in it and that helped for awhile. I didn’t replace the fuel filter. I’m not anywhere close to being a mechanic I just like to work on my own stuff and learn. I know Chevy fuel pumps you have to move the arm a certain way for it to work right but didn’t see that problem with my 318 motor. And the feller I bought it off of has the carb all of the open could that be my issue? Any help is appreciated sorry for the novel on it.

 

Make sure you got the pump installed correctly and then test the pump for flow and pressure. If thats all good, you have a problem elsewhere....

 

How do I check the pressure

 

Here is a general Idea.... >>>>>>