I'll try to be as clear as possible,

I have a FASS 150/95(older model) system on my truck, 98, 24v. Was having the typical fuel slosh/pressure issues. That being said, I put the Airdog in tank fuel pickup on the truck. Works great, slosh issues GONE.

My questions;

1. Why when I get to EXACTLY 9/16 on the fuel level gauge would the pump have a hard time initially priming the system?

2. Why when I hit a small bump/pothole on the road will the pump lose some, if not all, fuel pressure? Only happens with small bumps, big ones don't affect the pressure for some reason.

I have checked the wiring, everything appears fine. My thoughts were, A. The pump motor is going bad or, B. There is something wrong with the pickup tube inside the tank. Any insight is appreciated.

Thank you in advance,
Travis.

 

Don't trust the fuel gauge that you are actually just under half a tank. Mine will hang around half tank for quite a while, taking between 12-18 gallons to top off...

You may have a bad guage or guage wiring, I would also inspect that carefully.

Just a few thoughts.

 

Thanks, I had not thought of the f.p. gauge wiring. I'll look into that. The biggest thing that is troubling me is that it WON'T do it above a certain fuel level, tried to get it to do it. I don't know?? I'll have to look into all the wiring.

Travis

 

ISSPRO gauges with the isolator are known to do this....

 

NEVER heard of isolator systems doing this..... Isolators dont care how much fuel is in the tank. They either work or they dont, and when they dont, its because of a leak on the post side of the isolator. My take on whats happening is either related to the something electrical, like a bad connection or a bad ground whereby hitting bumps is affecting the lack of connection. Or there is a problem with the fuel module. If you live where corrosion is a problem from salt or calcium chloride, I'd look at electrical connections.

 

No leaks near the gauge, it's an Autometer 30psi unit. Just need to get time to check the rest out. Hope it's something simple.