So my friend has a 99 Freightliner tool truck dealio, which all the sudden died on him,

One shop put on a nice Fass lift pump ( factory one was dying i guess ? )

He winds up with a random no start, Next shop he went to, sold him a 2800$ VP pump,
and he still winds up with the no start when hot.

Then he finally calls me to help him ( i claim to know everything in the first place, so why not ? )

I run down the details with him, and tell him to unplug the lift pump, and see if it starts, calls me back and says " Yep sure does, shut the truck down, plugged it back in, and went back to a no start"

So with the help of a Innocent bystander, it took some unplugging and starting, then re plugging in the LP.

Long story short,
If the VP has allready been replaced, Do i demand that they warranty the " Reman pump from canada " and make sure i get one with the updated diaphragm ? Or is there another trick in the book ?

It's costing him 1000$'s and he wants this fixed ASAP !

Thanks
Nick

 

Does the lift pump run as soon as the key is turned on, if so, for how long? It should only run for half a second or so, just enough to push fuel into the pump, but not enough to pressurize it.

 

If i'm not mistaken, it was wired to the factory setup, so i'm not sure if it's momentary prime or if it's constant.

I know my truck is setup for the momentary, or if i bump the key it'll hold for 20 seconds.

Which makes me ask, why dose my truck start just fine with 20 second hold of 20 PSI ?

 

Is the FASS wires into a relay, or directly to the lift pump connector. A FASS may pull too much amperage for the poor little controller to deliver, and change starting characteristics.

 

Did this to mine and all is well.
( the second post )



https://www.dieselbombers.com/5-9l-2...lift-pump.html