Timberman

Well, thank God for my FP gauge. It slowly went from 13 psi down to 0 tonight, driving home. Had to drive it about 10 miles on 0. When I got home, I turned it off, waited a minute, and turned the key to on, and there was no LP noise, and the pressure stayed at 0. I did hear that "bump", I guess from the VP44, when you turn the key, but no lift pump. So I'm gonna put my old one on tomorrow and see if that helps.

Mine is mounted on the frame rail. Basically, I just disconnect the old one and hook up the new one, correct? I'm not sure what to do about bleeding the air out, will it do it itself or will I have to crack some injectors? I can't remember.

98.5POS

Bleed the line into the VP44 and then a couple of injector lines. Be prepared for a long process if it does'nt take right off.

piperca

Replace the pump and bump the engine a few times, just like you do when you do a filter change. You should be able to get her running pretty easy. In the event you don't, crack 3 and 5.

I'd suggest doing the aftermarket pump at this time, you will not regret it!

wildwood2500

before you replacelp is your fuel presser gage working right? i just put a new lp on mine,still shows 8 lb idle,****** me off" read about fuel senders going bad so i tapped on mine and now 13 pis at idle. now i have a spare lp.

Timberman

Well, I honestly don't know just what to think. I went out this morning and turned on the ignition, and the lp kicked on like normal. Gauge showed 0 psi. The pyro gauge was acting a little screwy, it jumped up to 1300 immediately when I started the truck. I turned the truck off and tried it again, still 0 psi, the pyro settled down and started acting right. I drove the truck around some this morning, now the gauge is at 2-3 psi, but won't respond to throttle, so I don't really trust the reading its giving me. I ran it hard from 5 to 80 mph once, and the gauge didn't budge. I just don't know, not gonna worry too much unless it starts running funny, I guess. I never have trusted the isolator setup.

wildwood2500

Iam getting a new sender,and putting man gage on the filter

piperca

When it starts running funny, it is too late!

The LP's motor will run, but there will be no fuel pressure, that is a normal symptom. I believe the motor is still spinning, but the impeller is stationary. The VP is capable of pulling 4psi on its own, but that's not enough to lube it ... have it checked out!

Timberman

I'll put my old pump on it and see how it does. Does anyone know what size flare wrench you need to crack the injector lines, I think it's like a 19 mm but not sure. Gotta buy one. Truck is a 99.

piperca

19mm is correct.

LonestarCTD

You shouldn't have to crack injectors if you're only working on the fuel lines from filter to tank, or even to VP for that matter. When I put in my Walbro and replaced lines completely from tank to filter and from filter to VP44, the lines were full of air but I was able to bleed them by bumping the starter. I bumped it like 5 times and then it took me 3 no-starts (got me REALLY worried when that happened), but on the 4th try after bumping 5 times, it fired full and steady. So, I figure you might want to bump like 8-10 times, try to start, and then if it doesn't start, let it rest, then you should get it to fire around the 2nd or 3rd try. I had all the air in the lines, air in the filter housing (I changed filter at that time), and in the lines from filter to VP and it still only took 5 bumps and 3 attempts before she fired and ran with no hesitation. Also, when you go to try to fire her up, mash the peddle about 1/2 way down. Hope this helps.

Joe Mc

When I installed my GFS-392 system it too was totally filled with air.

I suggest jog to "start" and let go, 3 - 4 times. Then, foot held to floor, crank for no more than 20-30 seconds at a time, then give the starter (and wires) a rest for 30 - 45 seconds and go again. It should start up after the 3rd or 4th time - run rough, sputter, smoke, choke - then smooth right out to it's normal cold idle. Always works for me.

Timberman

Thanks yall. Gonna mess with it today, with my old stock lp. I'd like to upgrade to something else like a fass or an aftermarket lp so I don't have to worry about it anymore.

tenbrooks

Go with the the walbro, cheap and easy

Timberman

Well, it gets interesting. I pulled the line off the output side of the lp and bumped the starter, got some fuel and alot of air. Turned to all air when the pump lost its prime. Found a big air leak on the lines over the tank, right in the 90 degree bend. Raised up the bed, undid the lines, unscrewed the big cap thing on top of the tank, and removed the entire in-tank assembly (which looks to me like it has some kind of sump pump in it). I guess tomorrow I'm gonna get the replacement for the whole assembly and see what that does. I know that some of you hate the in-tank pumps, but I don't see a way around it. Both lift pumps, the one mounted to the truck, and the one I tested from my tool box, seem to work fine. Any suggestions? Whoever designed the fuel delivery system for these trucks needs to be dragged out in the street and shot.

piperca

Call Vulcan and get yourself a Draw Straw. There's no need to throw away $400 on a new module. The Draw Straw will replace the damaged portion of the module and will run around $50. I did a write up over on another site, if you're interested, I can PM the link.