Gunch

Well I’d be guessing on the problem but below 1/2 tank you’d think maybe a pin hole in the pickup tube.But like Ollie said it puts more suction the lower the tank gets so man I don’t have a clue..But I had the same problem on a 3406 Cat but it was the check valve on the bottom of the pump but these engines don’t have a check valve

oliver foster

Since the problem started when you changed out the LP a couple of times...I would check the fuel line connections that where moved for that swap.
Make sure lines are on tight, clamp are working, O-rings are in good shape, ETC.

edwinsmith

I replaced the plastic fittings on top of the tank today. Took about 10 minuets to do with the bed cover removed. It's about 1/4 tank down from full so I'll have to drive it until it gets down below 1/2 tank to see if it did any good. Stay tuned.

Edwin

edwinsmith

Today I went to the grocery store and parked on a slight uphill. When I came out in 30 minutes the truck didn't want to start. It was still 3/4 full. So I guess I have to start swapping fuel lines again.

Would a problem with the return fuel system have anything to do with it?

Edwin

edwinsmith

I replaced the hose from the steel line to the fuel pump today. I'll see how it goes from here. The old hose was stiff but I only say a small crack on the end. Hopefully it was leaking there. If that doesn't fix the problem I think I can buy enough hose to go directly from the tank to the fuel pump to bypass the steel line. Anyone ever try this?

Edwin

Rug_Trucker

[QUOTE=edwinsmith;3377204 I can buy enough hose to go directly from the tank to the fuel pump to bypass the steel line. Anyone ever try this?

Edwin[/QUOTE]

Yep. I bought hydraulic/fuel line rated for B20. I ordered it from NAPA. Need the part number? I am done screwing with mine. I went to Dixie Diesel in Columbia TN. I am going to get mine hauled down there on a roll back. It's too damned hot outside and I need this truck on the road. I have tons of electrical stuff to do on it+paint. I will start a thread on it soon.

edwinsmith

Yes. The P/N would be good. There's a NAPA just down on 1st Street from here.

Rug_Trucker

Gates H313 Barricade carburetion hose that's for the 3/8" I got a 25ft roll. I was ****** at the counter guy because he couldn't find anything. I went home and found it and called it in. For the return line H312.

edwinsmith

Will a leak in the return line cause any problem other than a leak of fuel? I have no leaks just sucking air. Thanks for the numbers.

Edwin

edwinsmith

Found it!

https://www.napaonline.com/en/p/NBGH313

Edwin

Rug_Trucker

In theory? I am going to say no. I am frustrated with mine and and going to throw money at it. I can't handle wrenching on this thing in the TN humidity and sun. I was out in 43* drizzle working on this thing back in December. I can take the cold better than the heat. I don't think there was anything wrong with the factory lines. No leaks etc.

edwinsmith

At least here in the trailer park we have a canopy to park under while I crawl around on it. Most of my tools are in storage in OK though so I'm limited in what I can do. Hopefully I can get it figured out and not have to limp it back to OK with this trailer in tow. We don't leave until Sept. so I have some time.

Edwin

maybe368

Hey Edwin how are things besides your fuel problem? Take a good look at the connection into the lift pump. Mine had a hairline crack in the female threads. Good luck fuel system air leaks suck rocks😤…Mark

edwinsmith

Mark:

Things are good here in the land of fruits and nuts. I'm just biding my time while the wife trains her replacement at her work so she can finally retire. Then we're off to Oklahoma where we have a nice house and a separate garage on 2 acres. Then I can start living again.

I took the hose off but I didn't unscrew the angle nipple out of my piston lift pump so I don't know it's condition. When I first put it together U used teflon tape on it since it is a pipe fitting.

I have tried pressurizing the tank with air to see if I can find any leaks but no joy.

Hope you are doing well there in Phoenix.

Edwin

edwinsmith

I found this on NAPA https://www.napaonline.com/en/p/NBGH313

The picture shows 2 lines in a pair. Is that what you got?

I'm about ready to go get some and replace the whole line from tank to engine. I went out on Wednesday to drive it to Trader Joe's and it cranked forever before it caught. I went over and filled the tank which always fixes it and it starts fine again.

I'll do both the supply and return lines if the hose from NAPA is as shown in the picture.

Edwin