Fuel Systems?

[Badcop]

Im at a loss here, my CJ was originaly equiped with an under seat tank and mech fuel pump.

New running gear will have a rear mounted cell and inline pump. How do I determine what size pump I need? When I wire, will the pump just need to be on when the key is on?

I feel so stupid asking this, but im not in the mood to look it up since meat and shawn hurt my feelings yesterday...

 

[James K]

what is the motor going to be? EFI or carbed?

 

[Badcop]

what is the motor going to be? EFI or carbed?

carb 225, right up your alley, its all going in the 5, and I dont want to stay with the underseat tank, I want a cell in the bed in the rear.

 

[Bud]

a 10-15 PSI pump will suffice just fine then, might put an inline regulator so you can tune it easier. Mount the pump below your cell on the inside of fram rail or somewhere safe and as close to the cell as possible. Remember were mine is, same place. Go talk to old Doug or Jason at NAPA they know just what you need. We've used them a ton for the Howell and Holley Pro-jection fuel systems.

 

[Badcop]

a 10-15 PSI pump will suffice just fine then, might put an inline regulator so you can tune it easier. Mount the pump below your cell on the inside of fram rail or somewhere safe and as close to the cell as possible. Remember were mine is, same place. Go talk to old Doug or Jason at NAPA they know just what you need. We've used them a ton for the Howell and Holley Pro-jection fuel systems.

I might need to do that... Will the 10-15 suffice with a 4bbl 650?

 

[anvil]

With a carb you'll probably need something in the 4 to 8 PSI range. It's fine if the pump makes more than that, you'll just need a regulator to dial it down.

The PSI is only 1/2 of the equation. You need to know what volume the pump produces at a given PSI. For carbureted engines I like the Carter electric fuel pumps. Look at Summit Racing there are a couple just under $60. Any of them should work.

Wiring the fuel pump to turn on with the ignition is the easiest way to do it. You could also wire in a low oil pressure shut off switch. They aren't as useful on carbureted engines because they won't shut the engine off fast enough to offer much protection. If you really enjoy wiring you could wire the pump to come on for 3 seconds when the ignition is turned on then to turn back on when the engine is started. This way if the key is in the run position and the engine is off the fuel pump isn't running all the time.

 

[Badcop]

With a carb you'll probably need something in the 4 to 8 PSI range. It's fine if the pump makes more than that, you'll just need a regulator to dial it down.

The PSI is only 1/2 of the equation. You need to know what volume the pump produces at a given PSI. For carbureted engines I like the Carter electric fuel pumps. Look at Summit Racing there are a couple just under $60. Any of them should work.

Wiring the fuel pump to turn on with the ignition is the easiest way to do it. You could also wire in a low oil pressure shut off switch. They aren't as useful on carbureted engines because they won't shut the engine off fast enough to offer much protection. If you really enjoy wiring you could wire the pump to come on for 3 seconds when the ignition is turned on then to turn back on when the engine is started. This way if the key is in the run position and the engine is off the fuel pump isn't running all the time.

yah, not that good with wiring....

 

[snake]

3 to 4 PSI is plenty for a carb

 

[mbryson]

3 to 4 PSI is plenty for a carb

For a Briggs and Stratton? I've not had a carb for a while, but my smallblock Chevs and Buick motors all liked at least 7-9 PSI. (at least that's what I remember)

 

[way2nosty]

For a Briggs and Stratton? I've not had a carb for a while, but my smallblock Chevs and Buick motors all liked at least 7-9 PSI. (at least that's what I remember)

Quadrajet should be right at 8 for the best performance, if you go over 15 you will blow through the needle and seat and flood out, it's a common problem

 

[anvil]

Holley says the Truck Avenger should run at 5 to 7. I've heard 7 or 8 for a Q-jet. I've had no problems running a TA at 4.

 

[Crinco]

And be sure to put the Filter between the tank and the pump. Many pumps are gravity feed and will not prime well if mounted too high, Bud is right-on.
It really is a good idea to carry a spare pump too, a lot of those pumps don't last too long if they are ever run dry. One more thing, some people put a switch on the dash to cut off the pump, you can even hide it and use it for theft control. Older Jeeps can be pretty easy to steal. Just a thought.

 

[Bud]

And be sure to put the Filter between the tank and the pump. Many pumps are gravity feed and will not prime well if mounted too high, Bud is right-on.
It really is a good idea to carry a spare pump too, a lot of those pumps don't last too long if they are ever run dry. One more thing, some people put a switch on the dash to cut off the pump, you can even hide it and use it for theft control. Older Jeeps can be pretty easy to steal. Just a thought.

I learned that hard way about putting the filter between the tank and pump, oh and when you do make sure the flow is going the right way Brian! Good idea for the pump switch, dang thieves!

Question: Has anyone found clear silicone in their filter coming from an aluminum fuel cell from Summit? I did...just don't know if someone was trying to sabatoge my old crawler.

 

[Crinco]

Yes Bud, a neighbor bought one of their cells a couple years ago and they had put a layer of silicone around the top. It disolved (partly, it turns to mush really) and plugs up the filter and eventually makes it way to ruin your injectors if you have them, or carb I guess. He was PISSED. I would guess you aren't very happy about it either. He though it was a tank that someone else got first and they tryed to seal it up better before returning it back to summit. I am sorry to hear that is not the case as you got one too, huh? He pulled his foam and cleaned the tank, and I think he had to replace the line between the tank and pump just to be sure he got any residue. Nasty stuff!
Also remember that any silicone that gets burned in an injected engine will ruin the O2 sensor(s) too. But you already know that, just FYI.
Odd thing is, I got the same tank from them with no silicone on it!
Off-topic, I recently bought a fuel cell from summit, RCI brand ( I think thats what it was called), very impressed with the quality of that tank. Fit perfect behind the seat on a CJ7 too. 15 Gallon, rectangle, like 7" wide or so.