I installed a new FASS 150/150 Pump on my truck and now when I drop below 1/2 a tank of fuel It is hard to start. Anybody got any advise on how to fix the problem

 

Fuel leaks. I was been there done that. Check your check valve at the injection pump to see if its still functioning. Its on the return side of your injection pump. Check your suction line from the tank, sometimes the line isn't on all the way. I had a tee at the back of the engine that leaked as well as my o-rings on my injection connector tubes that leaked. You have a fuel pressure gauge? Do you get the quick pressure bump on turning the key to the on position prior to start?

 

Most likely it's a suction air leak. You probably won't see any fuel, but you can find it by placing a vacuum on the system. Double check all the fittings as well.

We had the exact same issue with a buddies truck after swapping to a mechanical setup. Installed correctly, but his definition of tight fittings differed from mine. That was all it took.

Dave

 

im not really a vp-44 guy but one of my buddies has on fass on his vp truck and his starts hard try unplugging or cut off the power to the fass with a switch to see it it starts any better his always does. I was told that the diaphrams or something in those pumps get weak and they don't like pressure on start up....sounds weird to me but hopefully someone will chime in and help more well.....good luck

 

Thanks guys now I have something to tinker with when I get off work