I spent the day Thursday meticulously installing a new fass system on my truck. I did the pump only and used a different filter bracket than the fass. I used all Parker store push lock fittings, copper line for the pressure gauge. I installed everything hit the key, it primed right up and held a solid 45psi. I went to work yesterday (my job requires me to drive this truck all day long) and when a got out of the grocery store last night I hit the key, got my pressure, then it just started dropping like it had no fuel. I could hear the pump running, but no pressure. I check under the truck and no leaks. I finally got it to run, but still no pressure. Took it to my friends house and we double checked EVERYTHING.

We pulled the line from the suction tube and stuck it in a can of fuel- nothing.
Blew air back into tank through the suction line, it was not blocked
Checked the return line spring in pump, looked new

Here's the kicker- we installed another new pump and same results

I finally got pressure by blowing air into the tank, it picked up prime and off it went. I'm going to drive around today and see what happens, also I'm going to switch back to my other pump.

What gives?? For the life of me I can't figure out what would cause this. I do have a full tank of fuel and this pump worked all day long. After my install I had appx 7 gallons of fuel in the tank, and now its full. Return line is clear.

Open to any and all suggestions. Thanks guys!

STUMPMAN's Sig:

94 4x4 automatic, Billet input shaft, twin disc torque converter, BD valve body, Gauges, 4"DP-5" exhaust, kdp kill,TC lock-out switch,Suncoast loc-up control,BHAF, S-300, DSS, Mag-Hytec front & Rear diff,trans cover, DDP 140 injectors,DDP DV's, ported exhaust manifold,70lbex. springs, 100 fuel plate, 4k spring kit, CFM+ Intake,FASS, O-ringed, arp studs, fuel press gauge, 18" Moto Metel 951, Road Armor bumper, 9500 winch,1995 2500 4x4

Is the suction line you are using rated for suction. If not, it could be collapsing on itself while the pump is running, even if you don't see it. Just a thought.

daveO's Sig:

98 Cummins 12v, QC, SB, 2wd, timing set to 17*, DTT 47RE, K&N FIPK 2, HTB2 62/14, ATS Arc-Flow intake, ATS Pulse Exhaust manifold, DDP High Flow Delivery Valves, DDP Stage 2 75hp injectors, 3k RPM GSK, TST #6 Plate full forward, AFC springs, AFC full forward, HX40 Style Downpipe to dual 5" Grand Rock Aussie stacks, Autometer Phantom II 2000* Pyro, 60 llb boost, trans temp.

Its the line that came with the fass system, I would assume so.

u got trash in the tank sounds like

hotcummins's Sig:

its a 12valve with a few performance adders

Glad to see you made it here Paul......I am wondering if you had air in the filters. When I change my filters I have to leave the fuel filter cracked open and turn on the pump until fuel come out of the filter and then tighten it back up and she's good to go. Another thing is if the tank is low that stupid and you stop short that fuel runs away from that damn draw straw and you'll lose pressure. It will come back up but the draw straws SUCK. I want to put a Hellman Sump in my tank to fix it.

PhilipR's Sig:

-Phil-98 Dodge Ram 2500 4x4,12V,47RE Suncoast Billet input shaft, Suncoast H/D Extreme Trans kit, Goerend Triple disc converter, FASS 150/90, FASS Suction tube, Amsoil Ea air and pre-filter, 100 plate, 4K GSK, 370's, AFC Mods, CoolerTubz intake, 5" stacks, BD-SBS, Autometer Z-series Pyro/Boost/Trans/FP, Amsoil front to back.

I vote air in the filters, Crack them open and It'll prime back. The new high flow modules will work for all these trucks, but you'll have to run the return line to a draw straw in the module instead of in the filler hose!

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Will that stop the problem of the draw straw sucking air at a 1/4 tank and under?

Sure will!

I assume that is the new Draw Straw I correct? DO you have them in stock? I am sick of that pressure drop around a 1/4 tank that I get with the FASS suction tube. PM me a price if you would. Sorry for jacking your post Paul....

I'll PM ya a price when I get to the shop. I'm at a buddies house right now.

Great. I appreciate it. I can't do anything until Monday any.

Thats ok Phil, I'm jacking your turbo

Nahh man it's all yours as long as I get to go for a ride after it gets installed. Plus if I install this new module this will fix your 1/4 tank issues as well....so i can be the tester.

Lucas could you post the correct park number for the guys that are sick of the 1/4 tank issues? thx.

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98 12V quad cab 4X4 AND 2001 24V quad cab 4X4

Ok...
I didn't see anyone ask,so I will....

Did you use the FASS drawstraw and mount it in the tank where they showed you?

What about the length of the drawstraw,did you possibly cut it a tad long thus it sucks closed by pulling the tank bottom up and blocking it?.

If you cut the drawstraw too short it will do exactly like you describe also.

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