| Auxiliary fuel tank [message #337345] |
Sat, 29 September 2018 06:11  |
Paul Nadel
Messages: 9
Registered: May 2013
Location: Lakeland, Fl
Karma: 0
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I am in the process of hooking up an auxiliary fuel tank. I have an adapter to connect to the Qjet that accepts a 5/16 fuel line.
Next I will try to find or make a cap for the fuel line coming from the fuel pump.
My question is. Is the best method to use a fuel tank from an outboard engine. The type that can be pressurized?
This set up is only for a few minutes and not to be driven.
I would use the fuel on board if it wasn't three years old.
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| Re: Auxiliary fuel tank [message #337346 is a reply to message #337345] |
Sat, 29 September 2018 06:22  |
Tilerpep
Messages: 404
Registered: June 2013
Location: Raleigh, NC
Karma: 7
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Senior Member |
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I have done it with a can in the passenger floor and ran the line into the mechanical fuel pump on the engine. It sounds like you are going straight to the carb, so I would think you would need the pressure can to get it started. Not sure if siphon and gravity would be enough to feed it. If you are reviving one that has been sitting, I would still try to use the existing pump. Pay close attention, because if the pump diaphragm is bad, it will let gas through sideways into the engine block resulting in diluted oil and quick death to the motor. So maybe just put new pump on (two port, not three) and run a can there. Pump is less than $50 if I remember and counts as one of the rubber items that need to be replaced for time, not just miles.
1975 Glenbrook, 1978 Royale rear bath
Raleigh, NC
[Updated on: Sat, 29 September 2018 06:24] Report message to a moderator |
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| Re: Auxiliary fuel tank [message #337347 is a reply to message #337345] |
Sat, 29 September 2018 07:15 |
Larry
Messages: 2875
Registered: January 2004
Location: Menomonie, WI
Karma: 10
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Paul Nadel wrote on Sat, 29 September 2018 06:11I am in the process of hooking up an auxiliary fuel tank. I have an adapter to connect to the Qjet that accepts a 5/16 fuel line.
Next I will try to find or make a cap for the fuel line coming from the fuel pump.
My question is. Is the best method to use a fuel tank from an outboard engine. The type that can be pressurized?
This set up is only for a few minutes and not to be driven.
I would use the fuel on board if it wasn't three years old.
Do not even turn that engine over until you get oil to the bearings. Gravity is your enemy. Over long periods of time gravity will drag oil off of bearing surfaces leaving them dry. If you prime the carb, and turn it over for immediate start, it will run for a period of time with out lubrication doing damage to bearing surfaces. Change the oil and filter to new 5W30 of your choice. Pull the distributor and turn oil pump with an electric drill until oil comes out of the rocker arms. This may take a while, but will insure oil to all bearing surfaces. Then pull the plugs and squirt oil in the cylinders. Now, with the plugs out, open the throttle and turn the engine over until you have good oil pressure. NOW you have oil on the bearing surfaces, and it is safer to put the plugs in, and start the engine. Bring engine to 1500-2000 rpm immediately to get oil to the camshaft. The 5w30 I mentioned earlier will flow quicker to your bearings. Now, if you wish you can change oil to your choice of oil weight. I've seen to many engines that sat a long time get a quick start, appeared to run good, only to be followed, within a couple hundred or more miles, a rod or main bearing go out. IMO, because of a lack of adequate lubrication on initial start-up. It won't hurt anything to do this, and may save an engine. JMHO.
Larry 
78 Royale w/500 Caddy
Menomonie, WI.
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| Re: Auxiliary fuel tank [message #337363 is a reply to message #337345] |
Sat, 29 September 2018 11:17 |
GatsbysCruise
Messages: 261
Registered: January 2017
Location: Waukegan, Illinois
Karma: 3
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Senior Member |
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I have had to use the extra tank with the power loss problem that occurred. The power loss was caused by a fuel loss or air leaking into the fuel lines from the fuel tank area, preventing the mech fuel pump from pumping fuel to the engine.
I basically used a tank with a hose in the opening, connected to the fuel filter that was before the mechanical fuel pump. So the connection was the temp fuel tank, hose, fuel filter, mechanical fuel pump.
The mechanic told me the fuel pump should be able to suck the fuel from the Temp fuel tank but I used a submersible fuel pump to prime the mechanical fuel pump and to fill the float bowl of the carborator. You can hear it gurgle as the fuel fills the float bowl. If you don't fill the float bowl, the engine will crank for a while till the mechanical fuel pump can pump enough fuel to begin filling the float bowl and start to feed the carborator.
The electric pump was only used to prime the mechanical fuel pump and fill the float bowl. then the elec fuel pump was shut off and the mechanical fuel pump could suck the fuel from the aux tank. Make sure your fuel line is at the bottom of the aux fuel tank so no air gets in the line.
A word of caution.. if you use an electric fuel pump and are unsure of the psi the fuel is pumped at, be careful if you use it to run while you drive. The higher psi elect fuel pumps can over power the float bowl floats and over fill the carb and gas will spill over.
The aux tank I used did not have a cap and was open to atmosphere.
I had to use this aux tank to drive the GMC during many tests trying to prove systems and locate the source of the fuel problem.
One big note here. If you have the mech fuel pump
with the third hose that returns fuel to the gas tanks, you need to run that third return hose to the aux tank to return the fuel or your 5 gallon fuel tank might as well only be a gallon. In my case, that return line moves a lot of fuel back to the fuel tanks and if you have the need to drive the GMC, your distance will be short because of that return gas hose sending gas to the fuel tanks.
For future, if you do not have an electric pump on your GMC, I strongly suggest that you add to your plans to install one before the fuel solenoid valve on the RES side, and connect the wire for 12v feed to the fuel solenoid pos so when you select the RES tank, the elec fuel pump will run. EVEN BETTER would be to connect the power to the OIL PSI SENSOR ( requires relay ) so if the oil pressure drops, the power to the electric fuel pump will be cut off.
The electric fuel pump was added to my GMC and was the only reason that I was still able to drive it with the fuel problem. The Elec Fuel Pump also gives you a chance to prime the mechanical fuel pump and fill the float bowl after sitting for awhile. SOme GMCs' tend to drain the float bowl after sitting (not good but happens with a certain problem with the carb float bowl) and I actually had the fuel drain back to the tanks, draining the fuel from my new mech fuel pump, and the insides of that fuel pump RUSTED. The following attempts to start the engine moved the rust to the carb and destroyed it.
Hope this was helpful.
slc
GatsbysCruise. \
74GMC260 Former Glacier Model style. \
Waukegan, Illinois \ Keep those MiniDiscs Spinning \ MY GREYHOUND IS FASTER THAN YOUR HONOR ROLL STUDENT \ WindowsXP-Win7-Win8.1-UBUNTU STUDIO - UBUNTU VOYAGER - Berzin Auto Center
[Updated on: Sat, 29 September 2018 15:06] Report message to a moderator |
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| Re: Auxiliary fuel tank [message #337422 is a reply to message #337397] |
Sun, 30 September 2018 15:41 |
midlf
Messages: 2212
Registered: July 2007
Location: SE Wisc. (Palmyra)
Karma: 1
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Senior Member |
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Run the oil pump with the drill.
Remove plugs and oil the cylinders.
Install the distributor.
DO NOT crank at this time.
Use large socket set and turn the engine through two revolutions. Stop and investigate if it jams at any point.
If OK so far then spin it with the starter.
This will find if any valves are stuck in their bores. If they are stuck you will damage things. Much cheaper to find out with the wrench than with the starter.
You may think three years would not allow enough time for the valve to stick. I can testify three years can be enough.
Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI
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