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HELP: No gas getting to carburetor

8

82ABNVET

New member
This winter I did an engine swap in our 2002 Glastron 205 SF. I upgraded from the carbureted 5.0 to the carbureted 5.7 and have been unable to get gas to the carb. I figured the fuel pump went out because it was getting power but not drawing fuel from the tank. I bought a new pump and filter and installed them but still no fuel. I sucked a mouthful of gas :( through the fuel line from the tank to the fuel pump, so I know there's enough gas in the tank. I checked the 7.5A fuel pump fuse and its good. I rebuilt the carb when I did the swap, but even if the accelerator pump wasn't working I wouldn't think that would affect the fuel pump from pumping fuel to the carb. But I'm no expert so any help would be appreciated.

thanks
 
There is, per USCG regs, a fuel pump connection to an oil pressure switch. No oil pressure, no fuel. On some engines, during cranking, this is bypassed and the fuel pump runs during cranking. On some setups, fuel pump only runs after oil pressure builds up.
 
Hi Seabass

On some V/Ps the fuel pump is powered via a relay which is activated by a voltage signal from a running (producing voltage) alternator. Remove the fuel pump relay which is at the fuel pump and place a jumper between the 30 and 87 female terminals in the relay block. Essentially the jumper wire will take the shape of the letter T across the terminal block. This should run the pump. Unlike a fuel injected motor, there is no priming once the key is turned to ignition. The only way that pump will normally run is if the alternator is producing voltage.

Hope this helps

Jon Allen
 
jon_allen said:
Hi Seabass

On some V/Ps the fuel pump is powered via a relay which is activated by a voltage signal from a running (producing voltage) alternator. Remove the fuel pump relay which is at the fuel pump and place a jumper between the 30 and 87 female terminals in the relay block. Essentially the jumper wire will take the shape of the letter T across the terminal block. This should run the pump. Unlike a fuel injected motor, there is no priming once the key is turned to ignition. The only way that pump will normally run is if the alternator is producing voltage.

Hope this helps

Jon Allen
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Hi Jon,

I will do this today and let you know how it goes. I really appreciate your help.
 
sandkicker said:
There is, per USCG regs, a fuel pump connection to an oil pressure switch. No oil pressure, no fuel. On some engines, during cranking, this is bypassed and the fuel pump runs during cranking. On some setups, fuel pump only runs after oil pressure builds up.
Click to expand...

Hi Bob,

Thank you for you reply, I did not know this but understand why they would design it that way for safety/fire reasons. I appreciate your help.
 
So I made a jumper wire between 30 and 87 and the pump came on. For whatever reason it's not pulling gas from the tank? I removed the filter and filled it with gas and it ran for a few minutes. I removed the main fuel line from the tank to the inlet on the filter housing and blew air theough it so I know there's no restriction there. I tried to remove the fitting on the tank to pull out the pickup tube but I can't get it loose. It's cold here and the tank is plastic so I don't want to force it and break the tank. Is there a filter on the end of the pickup tube that could be restricting it? Thanks
 
Hi Sebass

I would temporarily substitute a barbed fitting for the anti siphon valve atop the draw tube where the hose attatches. They can gum up and stick preventing fuel flow. Check the end of your hose for damage when you remove it. Lubricate it before sliding it on.

These new style ethanol resistant fuel hoses have a liner which can roll up if forced onto a fitting.

If this doesn't help you can blow into the draw tube with some low pressure compressed air which may clear debris from the tube/screen. This is a temporary fix, but at some point you will have to gain access to the tube. I would be very careful removing the tube from a plastic tank.

Good Luck

Jon Allen
 
jon_allen said:
Hi Sebass

I would temporarily substitute a barbed fitting for the anti siphon valve atop the draw tube where the hose attatches. They can gum up and stick preventing fuel flow. Check the end of your hose for damage when you remove it. Lubricate it before sliding it on.

These new style ethanol resistant fuel hoses have a liner which can roll up if forced onto a fitting.

If this doesn't help you can blow into the draw tube with some low pressure compressed air which may clear debris from the tube/screen. This is a temporary fix, but at some point you will have to gain access to the tube. I would be very careful removing the tube from a plastic tank.

Good Luck

Jon Allen
Click to expand...

Hi Jon,

I was able to remove the barbed fitting with the check valve. After doing so I cleaned it then blew some air through the elbow into the pickup tube.

After reinstalling everything I decided to check my old fuel pump and it wasn't bad after all.

After comparing the suction between the new and old pumps it was clear that the old pump had a stronger suction. So I reinstalled it but left the fuel line off that goes into the carb. I then used my jumper and within a few seconds had fuel going into my catch can.

I hooked up the fuel line line to the carb, removed the jumper wire, reinstalled the relay, turned the key and it runs great. Just need to put a light on it to fine tune the timing.

I appreciate your help Jon and for also teaching me how to jump and prime the pump. Couldn't have done it without your help. After it warms up I'll be removing that pickup tube to make sure it's fully functional.
 
Last edited:
To further add to your projects... Your boat is a pre-ethanol engine. You should replace ALL the fuel lines including the fill and vent lines. The linings on preethanol fuel lines are often solvent in ethanol and will dissolve and leave deposits in your carb (or injectors) that quite happily pass thru even the best fuel filters. Fuel filters catch particles, ethanol DISSOLVES, i.e. puts into solution, the lining of the fuel lines. When fuel evaporates in in the carb, the dissolved materials form a film and blockages in the carb. Some ethanol byproducts form a hard sand colored deposit that likes fine jets in the carb. This deposit is NOT soluble in carb cleaner products. Welcome to boating in the era of ethanol!!
 
sandkicker said:
To further add to your projects... Your boat is a pre-ethanol engine. You should replace ALL the fuel lines including the fill and vent lines. The linings on preethanol fuel lines are often solvent in ethanol and will dissolve and leave deposits in your carb (or injectors) that quite happily pass thru even the best fuel filters. Fuel filters catch particles, ethanol DISSOLVES, i.e. puts into solution, the lining of the fuel lines. When fuel evaporates in in the carb, the dissolved materials form a film and blockages in the carb. Some ethanol byproducts form a hard sand colored deposit that likes fine jets in the carb. This deposit is NOT soluble in carb cleaner products. Welcome to boating in the era of ethanol!![/

Thats a great idea, thank you for letting me know. I always use non-ethanol fuels in our small engine stuff but not in the boat. I'll add it to my list of projects. Thank you
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