Fuel system losing prime

[JAG1]

Sorry I did not get back about the tank vent till now. Been very busy working a lot .Any how the symptoms you have is definitly a clogged tank vent. The owner of Source Automotive who only works on the ram trucks said he's seen 4 or 5 like that. He said a couple had the fuel tank almost completely collapsed. You can add your own tank vent just in front of the filler cap inside the fuel door is where I have mine. I just used the filler neck vent hose and routed it to the new screened vent there. It does not make the truck fill slower nor overflow all over the paint this way Then put the return fuel line on the filler neck (what was the fill vent fitting). This way your not dumping the hot return fuel next to the fuel supply in the bottom of the cannister or module in the tank. Helps the injector pump stay cooler. This helps to see the return fuel by removing the cap. See how your truck's doing and able to better mix 2 cycle boat motor oil when you dump it in for fuel additive. Believe me you should go with 2 cycle for lots of reasons with this new goofey diesel.With the new tank vent put on with what was the filler neck vent hose from the tank you can add a few extra gallons since it vents enough to really fill up the tank. You should cut out those goofey in tank screens in the module and put on a real pre filter before the lift pump too.Anyhow there's a lot of info if any good... 2 cents

[Mopar1973Man]

JAG hit the nail on the head for sure. All really good idea and suggestions!

[olred92]

Sorry I did not get back about the tank vent till now. Been very busy working a lot . Any how the symptoms you have is definitly a clogged tank vent. The owner of Source Automotive who only works on the ram trucks said he's seen 4 or 5 like that. He said a couple had the fuel tank almost completely collapsed. You can add your own tank vent just in front of the filler cap inside the fuel door is where I have mine. I just used the filler neck vent hose and routed it to the new screened vent there. It does make the truck fill slower nor overflow all over the paint this way Then put the return fuel line on the filler neck (what was the fill vent fitting). This way your not dumping the hot return fuel next to the fuel supply in the bottom of the cannister or module in the tank. Helps the injector pump stay cooler. This helps to see the return fuel by removing the cap. See how your truck's doing and able to better mix 2 cycle boat motor oil when you dump it in for fuel additive. Believe me you should go with 2 cycle for lots of reasons with this new goofey diesel. With the new tank vent put on with what was the filler neck vent hose from the tank you can add a few extra gallons since it vents enough to really fill up the tank. You should cut out those goofey in tank screens in the module and put on a real pre filter before the lift pump too. Anyhow there's a lot of info if any good... 2 cents

Any pics of these mods?

[98.5]

ive been having the same issue on my 98, i'm running draw straw, raptor 150, and 2 micron cat filter, i have raptor and filter mounted under bed, where fass/air dog would be mounted due to how tall the cat filter is. i replaced pressure valve on the vp, replaced cross over tube o rings, checked tank vent, tried starting with fuel fill cap cracked. put a relay in so that pump would not run while engine is cranking. long story after over a month of tracking down this leak/ hard start issue and replacing the starter i decided to replace all the fuel lines and check the fittings. i fount that the line comming off the push lock fitting on my draw straw was starting to dry rot/crack just enough to let air in the fuel system. i cut an inch of line off and reinstalled the line on the draw straw. for going on 2 weeks it has started the first hit.

[JAG1]

Any pics of these mods?

I will do that today. Some of the plumbing is a little backyard mech but it works.

[oldschool]

Good luck!

[olred92]

Ok I was at Autozone earlier and just happened to question which fuel caps they had as this is where i had bpught the new one that is on the truck. He looked up the options of ones for my truck that they had and I found out that the one I bought a while is not a vented cap. They have a lockable vented cap but it is $20. My 98' Ram 1500 has a factory cap on it. Could i use it and see if it makes a difference. Idk if it being from a gasser will make a difference or not.

[JAG1]

The vented caps sometimes have a flapper, air can only go one way. Think it may restrict flow. I found one on the road still new and it fit my first gen truck so I use it. Needle nose pliers gets the flapper junk out. I knew to do that because this old truck has always had a clogged tank vent.Before I just drilled a 1/8th in. hole the non vented fuel cap. You drill only thru the first layer of the cap on the bottom so moisture doesn't go in the tank.I am sorry I can't get the pics on my fuel tank mods. I did go out and get the shots, waited for the sun to shine too, but, when I went to load them on my computer we cannot find the camera cord. Still looking

[oldschool]

The vented caps sometimes have a flapper, air can only go one way. Think it may restrict flow. I found one on the road still new and it fit my first gen truck so I use it. Needle nose pliers gets the flapper junk out. I knew to do that because this old truck has always had a clogged tank vent. Before I just drilled a 1/8th in. hole the non vented fuel cap. You drill only thru the first layer of the cap on the bottom so moisture doesn't go in the tank. I am sorry I can't get the pics on my fuel tank mods. I did go out and get the shots, waited for the sun to shine too, but, when I went to load them on my computer we cannot find the camera cord. Still looking

Excellent info on caps. I like the price too. Thanks Jag1.

[olred92]

The vented caps sometimes have a flapper, air can only go one way. Think it may restrict flow. I found one on the road still new and it fit my first gen truck so I use it. Needle nose pliers gets the flapper junk out. I knew to do that because this old truck has always had a clogged tank vent. Before I just drilled a 1/8th in. hole the non vented fuel cap. You drill only thru the first layer of the cap on the bottom so moisture doesn't go in the tank. I am sorry I can't get the pics on my fuel tank mods. I did go out and get the shots, waited for the sun to shine too, but, when I went to load them on my computer we cannot find the camera cord. Still looking

I will try that since the one off my gasser won't fit. The threads are different on cap.

[JAG1]

Personally I have heard about enough tank vents clogging that many could be marginally clogged and truck owners don't know it. I think the tanks need to breath better anyhow. It makes the lift pump work harder otherwise.