Hello folks,

Not too much of a chance for an introduction here, I just really need to get my truck up and running.

I'm finishing up a FASS install on my '01, and was wondering if there was a way to tell if an in-tank pump had been installed. I don't know the history, I've only had the truck for 6 months.

The original stock LP is still installed on the block, and had power to it before the Fass install. Is it usual for a block off plate to be put in when the in-tank retrofit is done by a dealer? Any way to tell without dropping the tank?

Right now, the truck starts and runs (quite well) but only shows 5-6 psi fuel pressure at idle. Also, it does make a sound like there is air being sucked in somewhere in the system. I've made sure that the fuel filter and water seperator are sealed well to the FASS assembly.

Maybe it is the sound of an in-tank pump not letting the FASS pull the fuel it needs?

Any ideas are appreciated.

 

Usually when an in-tank pump is installed the lp on the block is removed. Youve not run the fass though the stock lp have you? I ran a separate line from the fass directly to the injection pump. I hold 21 psi at idle.

 

No, the stock LP and filter was bypassed with 3/8" line from the kit.

I have my FP gauge plumbed in right before the injector pump; the isolator on it could be a problem, but today I made sure there is NO visible air in the line.

Hmm.

 

yea, could be the isolator. I know once i got air in the line and the guage went crazy, or it could be low on antifreeze. But a fass should hold more pressure than that.

 

Definaly check the isolator....Rebleed the diesel side of the gague as well. Any air trapped there would cause a low reading.

You can check for an intank pump (Granted this is all 2nd hand info from people i talk to on the phone) by seeing if there is a stock pump still in place (Which you said there was...but i have seen some still installed and a pump was found in the tank). You can also look at the tank sending unit wire harness plug. If there is more than 2 wires (Up to 4).....more than likely you have an in-tank pump.

You might check with a 5 gallon bucket test first...this will let you know real quick if you have a suction issue in the tank without pulling it down. I have seen stock modules cause issue as well.......

Im going to be out of pocket until wed.....but ill be here for about 30 more mins.....

 

First off, thanks for the help on the phone over the last day or two Dan. (This is Mark from NH). Your advice got the pump flowing, boy did getting the pump gears wet and filling the seperator get things moving. I'm just stuck at this final stage now.

I can't see any additional wires going to the top of the tank... I'll bleed the other side of the gauge once more and try the bucket test again if that doesn't do it.