Gas delivery problem 390 rebuild

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Sep 7, 2016 | 05:06 PM

mckoloum

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Joined: May 2014

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From: Sunny Florida

Gas delivery problem 390 rebuild

Hi all,

I tried to go for a spin earlier today and the truck started missing, and he ended up stalling not too far from home. I went to get fresh gas and put it in.
Everything is new, the engine have been rebuild with new pump, new carb, I didn't have any problem before. I have an inline fuel filter and it is a clear glass so I can see thru, it is not completely full with gas, and I can see some kind of junk in it (but that is the job of the a filter), like small particle of rust maybe!! The gas tank is brand new, I didn't drive the truck much since I finish the engine, so maybe since the rebuild not even 10 miles! I have hard time thinking the fuel pump could be bad, but it seem there is no gas going to the carb, yet I have to make sure of that, which is very difficult when you are on your own.
Anybody have any advice or explanation to what is happening?

Thanks

Laurent

Sep 7, 2016 | 06:52 PM

Steven@nd

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From: North Dakota

Was a new sending unit and pick up tube installed with the new tank? My pick up screen was rusted when I got mine, to the point that no fuel could be sucked out of the tank!

To check: remove gas line from fuel pump and pressurize the tank (not too much!) If fuel runs out your tank to the fuel pump is good.

Sep 7, 2016 | 08:06 PM

Blue and White

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Joined: Nov 2011

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Did you replace the short sections of rubber line between tank and pump? Reason I ask is I had a similar problem. I even had to tow her home once before figuring it out. The old soft rubber lines were getting sucked shut by the fuel pump. Alcohol + old fuel lines do not get along. A few feet of rubber fuel hose and a couple of hours fixed it.

Sep 7, 2016 | 08:32 PM

mikeo0o0o0

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Joined: Apr 2009

Posts: 14,333

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From: Stanley, VA

Another remote possibility. If your truck does not have evaporative emissions system, you need to use a vented fuel cap. Trucks with the system used a non-vented cap.
If you use a non-vented cap on the non- evap system, you can get an air lock and the pump won't draw fuel.

Sep 8, 2016 | 08:35 AM

mckoloum

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Joined: May 2014

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From: Sunny Florida

HI guys,
Thanks for the reply.
I had my mechanic who came last night to have a look, he just filled the carb bol with fresh gas, and it start right away with no problem!
I installed an inline glass fuel filter so I can see if gas go thru, and I was able to see some very small particle, it looks like rust!!!
Everything is new, gas tank.

Yes Mike I have the evaporative system, not totally hook up yet, and the gas filler neck is vented.

Blue and White, yes everything is new, new SS fuel line, new rubber hose.

Steven@nd I use the same fuel sending unit but replace the mesh screen, I
wonder if the screen moved away allowing small debris to go in the fuel line, but I have a filter so that shouldn't be an issue.

So everything seems fine, but I wonder why this did happen!!

My mechanic told me to fill the gas tank with recreational gas, the ethanol is causing the inside of the tank to rust with the fume!!
So now looking for Classic car insurance, so I can drive it to the gas station and fill the gas tank.

Sep 8, 2016 | 08:57 AM

4x4slik

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Joined: Jan 2014

Posts: 898

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From: Chillicothe, IA

Well, here is a few things for you. The junk you see in filter could be just from putting gas in it. Pick up screens and filters were put on these vehicles to keep out contaminates that got into the system by means other than just tanks rusting and fuel lines breaking down. When was the last time you saw a gas station replace it's underground tanks?

If you have one of those glass fuel filters with the replaceable elements, replace it. The elements are only 10 microns of filtering, you want 100. There is a member here who had to have his truck towed several hundred miles home due to the glass filter allowing small particles of crap in and clogging up his carb. Most parts stores sell a clear plastic 100 micron filter for just a few bucks.

Don't discount the fuel pump, could have been bad out of the box. Throwing a fuel pressure gauge on is not a bad idea to see if you have the pressure you should have.

Sep 8, 2016 | 10:52 AM

kwe45919

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Joined: Feb 2011

Posts: 575

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From: Knoxville, TN

Think most ideas have been stated here. Here's what I'd do.....

Replace all filters and screens first. Start it up and see if it works. If not, I'd disconnect the hose at the fuel pump and add vacuum or suck on the hose to see if gas is making it up to the fuel pump. If it is, next Disconnect fuel lines at the carb and crank. Is fuel getting to the carb?? If not, then it's very possible it is your fuel pump. If fuel is getting to the carb, then check your Carb as that might be the culprit.

Had to do the same check on my 390 after rebuild. Ended up my being the screens in the AN fittings at the carb, so, lesson learned, don't disconnect lines except at the carb, not before the carb when checking to see if fuel is making it up to the carb....of course my fuel lines are ran different than factory...

Of course everyone has their own way or steps...