How to prime a new fuel system Fitech

[Cortez]

OK so I replaced my fuel tank and my fuel lines and I’ve got to prime the system. I have an in-line fuel pump about 18 inches from a 23 gallon tank and I suspected it would draw the fuel into it but it’s not working what’s the best way to prime the system?

 

[Eoth]

Shouldn't need to "prime"..... Pump placement should allow it to be gravity fed. Inline high pressure pumps will not "suck" like a mechanical or low pressure pump.

 

[Cortez]

Right, but the siphon effect has to take place initially doesn’t it? The fuel pickup is at the bottom of the tank and the port at the top of the tank, with the pump equal to the bottom of the tank...it has to make it over the hump so to speak.

 

[rguest3]

The new fuel system not only needs to be primed but flushed as well.

Dismount the pump and the filters from the frame to make them lower than the tank. Unhook the EFI feed line from the T-body. Move the outlet back and lower to a fuel can behind the drivers side tire area. Turn the ignition on a couple times to prime the pump. Continue a few more times after the fuel runs into the can to flush the system.

Re-mount pump and filters then install fuel supply line when done.

 

[Cortez]

Thanks- will give it a shot

 

[DirtDonk]

What about pressurizing the tanks slightly?
Not as easy if yours is fully vented, but if it's a pre-'70 without the evap system, or if you can close it off temporarily, maybe you can apply some air pressure through the filler neck to force some fuel up the line.

How much gas is actually in the tank? Less fuel makes it a bit harder to start, but if it's full the weight should be easier to manipulate.

Hmm, rather than through the filler neck, if yours does happen to have the charcoal canister system connected, it might be easier to leave the gas cap latched and simply blow through the small vent line into the tank.

Paul

 

[DirtDonk]

Should have mentioned too, obviously you really only want to use a few pounds pressure. Whatever the minimum it is to see if this will work. Proof of concept so to speak.
Without trying to put 200psi into it!

Thinking something like 15lbs or less would be a good starting experiment.

Paul

 

[Cortez]

Hi Paul, It’s a vented tank (Sherman). I put about 4 gallons in. I was cautious not to put too much in case I need to drop the tank again for some reason. I’m just hoping it’s not an issue with the pickup tube being loose or too close to the bottom. The pressure trick might work actually...I have a non-vented cap so putting a little air into the vent line might just do it. I will try after work tonight.

 

[.94 OR]

It shouldn't take much air to get that siphon going.

I used that technique to siphon gas out of my sleds this weekend and it is surprising how little air it takes if you have a good seal. I just hold a rag over the tank opening around the siphon and air hose and burp a little air in until I can see the gas come through. Harder in your case since you can't see it, but you should hear it get to the pump.

 

[Cortez]

Finally got around to this yesterday and it seems like my pump is failing somehow...only has about 6 months of service before being parked for 18 mo. I suspect something has gunked it up, although I thought I drained the fuel system completely when I started this project. Won’t draw fuel from a cup 2 inches away. After that attempt I saw some residue down in the cup of fuel. Ordered a replacement to pick up today...hope this does it. Btw I did get the siphon going by pushing a little air in the tank...lines are clear. I wore some gas after that trick.