Mpg CJ 5, pollution stuff gone, I6, 4 speed

[Ctknorr]

What are the pros and cons of electronic vs mech fuel pumps?

Mechanical makes sense to me.




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[Lumpy Grits]

Mech can't put out the psi, that FI needs.
LG

 

[Belizean]

HH you might look into the cam for the FI. When I had my AMC 258 i6 / 4.2l machine work done I had to have a different comp cam ground for the FI, different from what was recommended for a carbed engine

 

[Hedgehog]

Never really considered the cam's affect on fuel injection.

One of my gripes about an electric fuel pump is the constant buzz. A fellow I work with has an electric fuel pump on a '69. The darned thing buzzes all the time, it's loud when riding in the thing. It is solidly attached to the frame. Yes, we both know he needs to figure out a way to dampen it. My MGB-GT had an electric pump and it wasn't bad at all, but it was designed for an electric fuel pump. A pump in the tank as the new cars have is the way to go.

 

[hole]

Hedge, I know the pump "buzz" your talking about. Not sure how much brand/quality of pump makes a difference or not. The pump on my 8 (not sure of brand) is only noticeable when I first turn on the key. Once she's running it's a non issue. IIRC , the pump was $200+ from Napa 10 + years ago and the spare all sealed up in bubble wrap cost me $220 from Napa a couple years ago. I got paranoid about a potential failure while in the middle of the desert, so I coughed up the $ to feel better. I also do the same thing with beer on my treks into the desert, its better to bring 20-30 home than possibly run out

 

[Torxhead]

The way I see it the big issue with an electric pump is keeping it full of gas, if not it can overheat and die. An in-tank pump is the way to go. Externally mounted pumps as I have do need to be mounted in a position where gas can siphon into them or mounted very close to the tank as their suction power is weak. The only time I hear mine is when I start the thing up and it is somewhat cushioned and wrapped in sponge to keep the vibration and noise down. I do keep an extra pump in the Jeep along with numerous other spare stuff. I no longer have the engine stall in off camber and steep hills. Also, fuel injection is a whole new can of worms if you have a lot of carb experience but well worth it.

 

[Lumpy Grits]

Do these pumps go inside the tank or frame mounted near the tank?
If frame mounted-Use a 'insulator'(folded over, old inner tube)between the FP and frame.
LG

 

[Torxhead]

From what I understand Lumpy, there are two locations where an external electric fuel pump can be mounted, I am not sure which works best. One location would be as close to the tank as possible, which would be on the frame crossmember just in front of the gas tank. This allows the pump to pull the fuel in and push it into the fuel pressure regulator. Low restriction filters are placed in front of the external pumps to protect them. The other location would be at or below the level of the fuel tank which allows the fuel to siphon into the pump, this would be along the frame near the skid plate. Like I said the best place would be in the fuel tank where it would be kept cool and have closer access to pump fuel. The external version does have better filtration as the in-tank version has only the sock. The external pump is also easier to change out. Keeping plenty of fuel in the pump is a must so it does not overheat.