Fuel starvation conundrum

[airshot]

I bought a small 12v electric fuel pump off Amazon for fuel for less than 15 bucks shipped. Works great for pumping out fuel tanks from snoblowers, rototillers and other toys that need fuel emptied each year. Set a 5 gallon can on the ground and let it rip. By mixing 5 gallons into your car, truck or other vehicle, you won't be throwing it away or having to dispose if it. Over time it will all be gone and you can start next year with fresh fuel.

 

[rolmops]

Good thought! I checked the vent, I think it's clear, who knows with that old fuel line though. I "think" the hoses were original if you can believe. It's a 1988 boat!

My boat is an 89 and it had the original fuel hoses, that is, what was left of those hoses. The filler hose was mostly rotten and sweated fuel onto the foam, while the air hose was completely dried out and crumbling. I would never have found out If I would not have taken the floor out in order to inspect the foam. Ethanol is quite a destructive force for certain types of rubber. Never mind the engine not running perfectly, you may be boating on a bomb that is ready to explode any moment

 

[Lou C]

My boat is an 89 and it had the original fuel hoses, that is, what was left of those hoses. The filler hose was mostly rotten and sweated fuel onto the foam, while the air hose was completely dried out and crumbling. I would never have found out If I would not have taken the floor out in order to inspect the foam. Ethanol is quite a destructive force for certain types of rubber. Never mind the engine not running perfectly, you may be boating on a bomb that is ready to explode any moment

the ones in this boat are dried out & stiff but not crumbling but i do plan to replace them...

one last thing I noticed...the ID of the old fuel supply hose to the engine (3/8") seems bigger than on a new section of hose of the same size.....wondering if they could have been sucking in air even though the clamps were tight and there were never any fuel leaks....
I tested the old fuel line with my vacuum tester and it held -10" hg but that doesn't mean it held vacuum at the connections at the tank & fuel filter.....

 

[airshot]

When E fuels came to market, it was highly recommended to change fuel lines over to E rated fuels to keep the old type of hoses from failing. How many folks did that ? My neighbor collects old cars, a out 12 or thirteen from 70-80's. He went thru and replaced all the fuel lines that were made of rubber and converted to the E fuel safe hoses. He does add a fuel stabilizer to his E fuel that he uses in his vehicles. Have known him for over 20 years and no E fuel issues, and neither have I..

 

[Lou C]

Still looking for the smoking gun....
I rigged this up to test the old fuel pick up tube and anti-siphon valve for vacuum leaks, it's holding at -11.5"hg, I left it hooked up in the garage and will go out later to see if it holds or not. A section of the old fuel line is on the end with the anti-siphon valve, to see if it was porous or not....
I'm not sure what vacuum a fuel pump typically pulls, gotta find that out, but if this holds, it leaves only the fuel. The boat ran perfect on the outboard tank, so I thought for sure there'd be a problem with the anti-siphon valve, pick up tube, or fuel line, but so far.....


PS I tested the old anti siphon valve against an identical new one (OEM BRP anti siphon valve) and with the vacuum pump they test identical both open at -1"hg.
Got my answer about fuel pump vacuum from my OMC shop manual, should be -9"-10"hg. So if this holds at -11.5", it was not the cause of the problem.....

 

[dingbat]

When E fuels came to market, it was highly recommended to change fuel lines over to E rated fuels to keep the old type of hoses from failing.

E10 rated hoses have been OE in the auto industry since 1989.
The OE fuel hoses is my 1997 boat where E10 rated.
Don't know about others.
Complete hose refit in 2012.
Fill hose was permeating at bend

one last thing I noticed...the ID of the old fuel supply hose to the engine (3/8") seems bigger than on a new section of hose of the same size.....wondering if they could have been sucking in air even though the clamps were tight and there were never any fuel leaks....

The drying out and permanent deformation of the hose at the bib is normal.
Even if the hose is still in serviceable condition, best practice is to trim the hose back past the bib before reassembling.

 

[Lou C]

Yep I had done that several years earlier.
All the old hoses on this boat are gonna get replaced.

 

[airshot]

Many of the E rated hoses were junk and lasted only a few years. When mine went bad in less than 3 years, I replaced it with premium A15 fuel line.
The gray stuff sold at retail stores is the junk stuff.

 

[dingbat]

Many of the E rated hoses were junk and lasted only a few years. When mine went bad in less than 3 years, I replaced it with premium A15 fuel line.
The gray stuff sold at retail stores is the junk stuff.

I wouldn't say many……the cheap grey, “outboard” hose sold at the big box stores was junk…lol

 

[Pmt133]

I've had a few of the cheaper lines (cars) swell internally and become porous with ethanol fuel even when rated for E10. Coincidentally the good automotive line isn't much cheaper than the marine stuff.

 

[dingbat]

I've had a few of the cheaper lines (cars) swell internally and become porous with ethanol fuel even when rated for E10. Coincidentally the good automotive line isn't much cheaper than the marine stuff.

Lead the Mechanical Design group for a numbers of years. Knew the Parker and Aeroquip catalogs like the back of my hand.

Got called into a meeting last week to give my opinion on a hose failure. Couldn’t believe the difference in supposed “OE” quality hose between now and back in the day.

Turns out the hose was purchased from a well known, third party parts supplier. Upon investigation, supplier admitted they source open market. Sent a generic data sheet to support the product

Buy card now gives instruction to purchase specific, name brand hoses

 

[Lou C]

I think the same thing happens to automotive OEMs with their suppliers. When the OEMs put price pressure on them they look for other sources. I get my stuff from a marine supplier who supplies all the bigger boatyards in my area. Cheaper than West Marine and the guy knows everything!
Going to get the fill hose and vent hose from him too…

 

[Lou C]

Update:
vacuum test didn't hold over time but I'm not sure that's such a valid test.
I am going to do a pressure test with soapy water to see if there are any leaks in the tube, anti siphon valve and old fuel line.
for testing the fuel, I think I'll siphon out a gallon or 2 and see how it runs in my pressure washer....
if it's good now, I'll test it again in the spring....it's not gonna beat me...lol...

 

[Chris1956]

Did you hook up the remote tank to the water separator?

The water separator is clean and sans water?

Does the fuel pump have one of those porous stones on it? Does the carb also have a paper filter on the fuel inlet? My '88 MerCruiser 4.3LX did. They last a long time, but not forever.

 

[Lou C]

Ya and yes. My QJet just has a screen in the fuel inlet that was replaced when I rebuilt it this summer. Gonna do a pressure test and see what that shows.

 

[dingbat]

vacuum test didn't hold over time but I'm not sure that's such a valid test.
I am going to do a pressure test with soapy water to see if there are any leaks in the tube, anti siphon valve and old fuel line.

One of the components we manufacturer is a high voltage transformer filled with insulating oil under vacuum.

I've never got a straight answer as to why exactly, but components that leak under vacuum rarely leak under pressure and vice versa.

 

[Pmt133]

Lead the Mechanical Design group for a numbers of years. Knew the Parker and Aeroquip catalogs like the back of my hand.

Got called into a meeting last week to give my opinion on a hose failure. Couldn’t believe the difference in supposed “OE” quality hose between now and back in the day.

Turns out the hose was purchased from a well known, third party parts supplier. Upon investigation, supplier admitted they source open market. Sent a generic data sheet to support the product

Buy card now gives instruction to purchase specific, name brand hoses

The hose in question I had replaced was the OE goodyear... I want to say fluoroelastomer or something similar printed on it and date stamped 1983... that didn't dryrot, leak or anything odd. Obviously what replaced it didn't fare as well. There really is alot of garbage out there now.

 

[Chris1956]

OK, another SWAG. My '88 SeaRay had a filter in the fuel pickup tube. You needed to unscrew a plain tube of aluminum to get to it. When it partially clogged, the motor only got enough fuel for low to medium speed.

 

[Lou C]

I've heard of those causing trouble, the original one was just an aluminum tube screwed into the square fitting, no screen. The one I replaced it with (Moeller) also has no screen. When I took it apart, it was completely clean, no debris in the tube or anti siphon valve. Bottom of tank was clean too from what I could see through the hole.


Literally every year when I get the boat going in the spring I dump out the fuel from the previous year's fuel filter and it always looks like this.
No debris in the fuel, no layer of water, no bad smell.

 

[Lou C]

Ok tested the old pick up tube/anti siphon valve & fuel line. Pulled a vacuum of 10”hg held steady for 2 hrs. Also tested under pressure 10 psi with soapy water on all connections and no bubbles no apparat leaks. What say you I boaters? Back to the bad fuel idea? Only other thing I can think of was there could have been an air leak where the old fuel line attaches to the fuel filter because that was disconnected a few times over the years and the hose might have been a little stretched. Remember it ran perfect on the OB tank with fresh fuel & new fuel lines….