Fuel delivery nightmare

[RiverPatrol]

I'm throwing it out to the brain trust for suggestions.

The weather has warmed up and I gained some motivation to try and get the green soft top running while it's waiting for its new forever home. I managed to get a new battery in it without too much difficulty. It cranks strong.

I knew the gas in thank was bad, it had quit smelling like varnish a couple of years ago when I walked past. Taking several deep breaths of resolve I got down underneath the tank with a couple of drain pans, a crescent wrench and some rags. Got the drain plug off without too much trouble. The gas came out an amber color, smelled horrible, but it was clear and there was no debris. Dealt with disposal and cleanup of that mess, got rid of the smell so the neighbors wouldn't be concerned. I had a couple gallons of fresh gas and a couple gallons of old gas that smelled ok - I think it must have been from Parker, AZ so that stuff lasts longer because it doesn't have all of our CA crap additives. I know the Patrols are very forgiving on the quality of the fuel they require, they will run on just about anything as long as it has a little octane.

Cranked the engine for a good long time off and on but the glass bowl fuel filter isn't getting any gas in it. I notice that the accordion type filter looks a little ugly and there is some junk at the bottom of the bowl so I take it apart to clean it up. The fabric on the filter disintegrated so I replaced the filter with a new element and spring. Put it back together, cranked some more - no bueno.

I pulled the fuel pump off to bench check it. It bench checks ok so I put it back on, still nothing. I grab the vacuum gauge and hook it up to the fuel filter outlet and pump it several times. This brings gas into the fuel filter bowl. I hooked the fuel pump back up and crank and it draws some fuel into the line but only anemically. Check my inventory, I have one rebuilt fuel pump available. I install it and crank and it fills the fuel filter bowl all the way but does not get any fuel to the carb. Much head scratching.

I decide to rebuild the old pump because I know it worked the last time I ran this Patrol. Research, get the proper kit from inventory (this fuel pump has the primer so it's an early one). Clean up the fuel pump and take it apart - the diaphragm was indeed leaking. Verify that the diaphragm stem is the correct length in the kit, rebuild the pump and reinstall it. Still no bueno. More head scratching. Now I'm frustrated and out of ideas, I reach out to Esteban for suggestions. I also search the forum and find this thread where faux40 had a similarly perplexing issue: viewtopic.php?f=21&t=2350&hilit=fuel+pump&start=360 . Interestingly, his fuel pump was identical to my rebuilt pump. Comparing the two now I can see some differences on his that may have contributed to his issues.

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Esteban gives some suggestions, some that get me thinking in different directions. He mentioned the cork seal on the fuel filter, how they don't like to reseal after being apart. I happen to have 2 of the unicorn cork seals for this so I installed a fresh one on the filter. He also mentions trying to run a line from the fuel pump inlet to a gas can, see if fuel gets to the carb that way. So I tried this, cracked the line at the carb so I would know if fuel was getting up there, got a little bottle and filled it with gas, put together a line and fitting to the fuel pump. Cranked the engine a bit and the engine actually fired up and ran, and ran well! Success! Now to further investigate.

Fired up the compressor to blow out the lines. I can get air through the fuel filter but when I try the inlet line to the filter back to the tank I am getting blow back, it's not blowing into the gas tank. Go back to the tank and remove the inspection cover and remove the outlet fitting. I can blow air into the outlet line just fine, no restriction. This tells me there must be blockage in the tank. Picking Esteban's brain again, he suggests trying to blow air into the tank from the outlet fitting. With the tank in the vehicle this just isn't possible, there isn't enough room for me to try and get a hose securely on the fitting. It is not possible for me to drop the tank, I am already pushing my abilities.

I decide to run something down the line to see if I can feel blockage. I have some good stiff baling wire to try. I can push it in what seems like all the way to the bottom of the tank before it won't feed in anymore. When I pull it out it isn't caked with crud but it also isn't wet with gas. Out of curiosity I removed the gauge sending unit to get a look in the tank. There is some stuff at the bottom of the tank but nothing that looks like it could solidly plug a line. Certainly nothing that would plug the line solid since the last time it ran.

I am out of ideas. And I can't pull the tank, I'm just not capable of everything involved with that. Just doing what I've done has been pushing my limits.

[50car]

One thing to consider is if the fuel tank had water in it for an extended time, the fuel pickup line may have a rust hole in it or it may be cracked allowing air to be drawn in rather than fuel. May want to see if you can see the fuel pickup line with cover off the tank.

[RiverPatrol]

One thing to consider is if the fuel tank had water in it for an extended time, the fuel pickup line may have a rust hole in it or it may be cracked allowing air to be drawn in rather than fuel. May want to see if you can see the fuel pickup line with cover off the tank.

A good thought. The fuel pickup line is not visible in the tank when I took the sender out, there is a baffle in the way. There wasn’t any water in the tank when I drained it. The part of the pickup line outside of the tank is fine, not even rusted. It wouldn’t seem that a crack in the pickup would block air from being blown through though.

[G60michael]

Hi River, only briefly read over what you've already done, here's a couple of ideas you could check.

How is the breather, check its not blocked.
Remove the Fuel cap and see if it will draw fuel up then

Get an air nozzle and rag and seal your hand around the filler neck and try and pump some air into it see if it will push the fuel up to the filter, then start it and see what its done.

It maybe suffering from some kind of Vacuum lock in the tank.

[Esteban]

Very frustrating all that you are going through with this issue RiverPatrol.

I don't see any other option than to blow compressed air into the tank outlet fitting. Since space is very constraint there, making it almost impossible, the other option could be at the inlet of the glass bowl filter. Also space is very tight there, and might require taking the fuel filter out. The key could be making a tight fit for the compressed air no to scape, maybe using a piece of hose with clamps.

The blockage of the fuel line inside the tank looks to be serious, and only a blast of 80 to a 100 psi of compressed air might be able to free it. If it doesn't, dropping the tank will be next, but we know this is impossible to do for RiverPatrol alone.

[RiverPatrol]

Hi River, only briefly read over what you've already done, here's a couple of ideas you could check.

How is the breather, check its not blocked.
Remove the Fuel cap and see if it will draw fuel up then

Get an air nozzle and rag and seal your hand around the filler neck and try and pump some air into it see if it will push the fuel up to the filter, then start it and see what its done.

It maybe suffering from some kind of Vacuum lock in the tank.

Thanks Michael, all good considerations. The tank vents plenty well though. I had cleared and replaced the vent hose a few years ago, and the gas cap gasket is so old it doesn't provide a good air seal. I don't think it would be possible to get a good enough seal to try and blow air into the filler neck and have it do any good. But there are some good ideas there, maybe I can expand on it.

[RiverPatrol]

Very frustrating all that you are going through with this issue RiverPatrol.

I don't see any other option than to blow compressed air into the tank outlet fitting. Since space is very constraint there, making it almost impossible, the other option could be at the inlet of the glass bowl filter. Also space is very tight there, and might require taking the fuel filter out. The key could be making a tight fit for the compressed air no to scape, maybe using a piece of hose with clamps.

The blockage of the fuel line inside the tank looks to be serious, and only a blast of 80 to a 100 psi of compressed air might be able to free it. If it doesn't, dropping the tank will be next, but we know this is impossible to do for RiverPatrol alone.

I've got the fuel filter removed right now so access to the the inlet line is clear. I have a hose on that end and that's what I've blown the compressed air into. It's a tight seal, no air escapes anywhere until I release the air nozzle. I guess I'll just keep trying that and running the baling wire down the pickup tube a few more times. Something's gotta break loose sometime you'd think.

[mad4hws]

I wished I lived closer. I could come over and help you out. Not sure the result would be any different though. It will break free eventually and you will win

[RiverPatrol]

I wished I lived closer. I could come over and help you out. Not sure the result would be any different though. It will break free eventually and you will win

Aw, thanks. lol What's mind boggling is trying to understand what could possibly have formed such a strong blockage while it was simply sitting.

I think I might head to the hardware store and find some larger gauge wire, have a go at that aspect again.

[Flaggoni]

Couple ideas... I’ve found the inner cable of a speedometer cable to be useful in poking through plugged lines. Perhaps spin it with a non-sparking drill motor?
Also, since all these vehicle have POs, there is a possibility of an unused, yet not removed electric fuel pump still lurking in a the supply line.
Good luck ! Keep at it!
Mild Bill