AMC 258 fuel delivery issue

[72jeeperjoe]

My Jeep was running great until a week ago I started it up and ran it, no issues, ran fine, then it just died while running. I believe my gas gauge is accurate however to be safe I put 5 gallons in it. It still would not start, replaced fuel pump and no gas still. Replaced the replacement fuel pump with the same style pump but different brand, still no gas. I blew out all the lines, no clogs all the way to the tank which has been cleaned, replaced all the rubber lines, new filter and still can not get gas to the lines. I am on the third pump, new lines, clean tank and still no gas. Has anyone else had this issue? if so how did you fix it? I am assuming worse case scenario I have a bad cam, but would that completely stop any pressure to the pump. Any help will be greatly appreciated, Thank!

[twmattox]

Was your fuel sock on the sending unit? If that fell off, you would need to have a lot more fuel in the tank just to reach the lines.

[tenoverthenose]

You've said you can't get gas to the lines - I'm not 100% sure what you mean. Have you verified that you are getting fuel to the carb? It sounds like you've replaced a few things already, but I would check the fuel at the carb and work backwards.

My guess is that there is a small hole in your hard fuel line between the pump and the tank. If that's the case, you will just suck air without ever getting fuel. You could always run a new line between the tank and fuel pump as a quick test. It's happened to me before...

[tgreese]

Year/model/equipment? Assuming it's a '72 FSJ with a 258.

A more common problem is a hole in the rubber line on top of the fuel tank. If you have a MityVac or generic equivalent, disconnect the fuel pump and see if you can pull fuel from the tank. Then see if the fuel pump spurts when you crank the engine. Divide and conquer.

[72jeeperjoe]

Thanks for the replies guys. After some more checking today, I am getting good fuel from the tank with little pressure, check the lines and no cracks. I am not getting any pressure at the pump, in or out so it does look like a flat cam unfortunately. Just to make sure there is no fuel pump rod on the 258's right? It is an 83 btw. Thanks

[tgreese]

IIRC it rides on the cam. There's a cutaway picture in the TSM. Kind of unlikely the cam would wear away where the fuel pump rides. That's a very low load compared to the lifters. I would be more suspicious of the pump. You should be able to look in the fuel pump hole and see the cam. Mirror, flashlight, etc. If you move the pump lever by hand the pump should spurt. You can also put the input side of the pump into a can of gas and see if it will pump that way.

[72jeeperjoe]

The cam has 323,000 miles on it so there is a fair chance for it to wear out, have had it happen before. The pump is functioning fine and there is no leaks from the tank to the pump, lines hold pressure just fine. I can get pressure to the pump without an issue however there is no pressure from the pump, all three pump do not have enough pressure to send fuel to the carb. Taking the pumps and holding them to the cam while the engine rotates does not move the arm on the pumps, showing that the cam lobes is flat. So it looks like its time for a new cam. Thanks for the responses.