1956 CJ5 Fuel system replacement

Ia2003

New member
I just removed my fuel tank from my 56 CJ5 because it was leaking and had debris and rust flakes in it. Should I put in an original style metal gas tank or a newer style plastic variant? Also, when I pulled out the fuel line it was black rubber hose, not the original metal line. I am leaning towards putting new rubber hose in because it is much cheaper. Is there any reason to put in the metal lines? Thanks everyone.
 

metal or plastic is entirely up to you... metal is more authentic, plastic isnt going to rust... i actually had a fuel tank rust completely through once, but it does seem no matter what you do, rust flakes are never a good thing getting into your engine... id probably go plastic

and there is one good reason for a metal line, but only if you plan on using alcohol for fuel... but as metal ages it corrodes, as rubber ages it dries out and becomes brittle.. so i dont think itll matter much
 
I replaced the fuel tank with a plastic tank and sending unit from MTS automotive. I replaced the line with a rubber line. I installed an online fuel filter. I was able to start the jeep with a lot of difficulty. Once it started I let it idle for about 20 minutes and it still ran. This tells me my new fuel system is working. However, the engine stalled. I retarded and it died every time I put it in gear and tried to move. This happened over and over for about half an hour. I gave up for the day and am completely stumped. Why would the engine keep stalling? I am having the same problem I had before replacing the fuel system. Suggestions? Thanks!

-Ian
 
try a seafoam treatment to clean out your engine as best you can.. since its a CJ5 i doubt you have a bunch of useless sensors causing issues, so it may be a carb issue.. or youre losing compression in the engine itself... could also be electrical.. does it start back up after it stalls or is it hard to start up?
 

Usually it is hard to start back up once it stalls.
 
Ia2003 said:
Usually it is hard to start back up once it stalls.

I should note that it is hard to start because the battery is always dead. A separate issue, something is draining the battery slowly so I have to slave start it.
 
If the tank had rust in it you might want to remove and clean out the carburetor. Rust dust will get past many filters and settle in the carb. Surplus City Jeep Parts probably has a Jiffy Kit for it (which will have all of the gaskets, a needle and seat, and other parts you need). Jiffy Kits also tend to have extra parts for other models to add confusion to the project - carefully check each old part to its new replacement and be sure all holes, etc line up. Do NOT run wire through any holes that are calibrated (like near the main jet) unless you are very careful not to mar them up. Also, be sure there are no other fuel filters in the line (which could be clogged with rust). How's the fuel pump? It may need to be rebuilt also. The old diaphrams generally don't like the new gas. There could be a screen and sediment bulb on the side of the pump. Be sure this is cleaned out too (the screen is at the top of the glass bulb, in the "roof" of the bulb holder). Hope this helps... Best of luck -John
 

IIRC the plastic tanks have had some cap sealing and or cap venting issues. Maybe you are pulling a vacuum in the tank.
 
Crazy4diesels said:
If the tank had rust in it you might want to remove and clean out the carburetor. Rust dust will get past many filters and settle in the carb. Surplus City Jeep Parts probably has a Jiffy Kit for it (which will have all of the gaskets, a needle and seat, and other parts you need). Jiffy Kits also tend to have extra parts for other models to add confusion to the project - carefully check each old part to its new replacement and be sure all holes, etc line up. Do NOT run wire through any holes that are calibrated (like near the main jet) unless you are very careful not to mar them up. Also, be sure there are no other fuel filters in the line (which could be clogged with rust). How's the fuel pump? It may need to be rebuilt also. The old diaphrams generally don't like the new gas. There could be a screen and sediment bulb on the side of the pump. Be sure this is cleaned out too (the screen is at the top of the glass bulb, in the "roof" of the bulb holder). Hope this helps... Best of luck -John

Thanks, I rebuilt the carb and everything in the fuel system. There is only one fuel filter. I took the advice of one of the above members and sprayed a can of sea foam into the carb. After that all the symptoms have disappeared and it runs beautifully! I do wonder if I should be putting a lead additive into each tank of unleaded gas? Thanks for everyones ideas, I'm glad to have gotten my jeep running!
 
Stock 56 engine? Yes you need some lead additive, unless you hardly drive it. Your heads do not have hardened exh. seats or valves that can tolerate unleaded easily.
 
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