mechanical fuel pumps keep quitting after they sit. what am i doing wrong?

[kickitandholdit]

ok so my jeep isnt getting gas and the lines are all new and new filter and new gas tank and new gas. my fuel pumps keep screwing up. i can replace the fuel pump and it runs like a top but once i let it sit for a week or so the fuel pump will quit. i have pumped the gas and tried to crank it many times and there isnt any gas in the filter but i know if i go get a new mechanical pump and put it on it will run like a top again. this has happened 4 times in the past 2 months. the lobe on the cam is in good shape btw. im seriously about to go to the custom marine boat store and buy a bulb to pump so i can prime it or something haha. i know its a jeep but this is getting a little ridiculous.

 

[CJ]

A AMC 258 i6 / 4.2l ? Man, I have no idea. Did they all come from the same source? Maybe a bad bath of pumps?

 

[kickitandholdit]

yep and they did all come from the same source. one was in stock and the others were sent in though so im sure they are far apart on the line. idk it doesnt make since to me?

anybody know where i can get a plate to cover up the hole on the side of the block if i decide to go to electric?

i might get an electric to back up the mechanical.

 

[73CJ]

Wow 4 pumps? Maybe try a NAPA or something. Summit sells block off plates, but aren't hard to cut out of a plate.

I've had good luck with a Holley electric pump.

 

[Johnboy]

I beleive not for sure but if it shares the same simialar bolt up like the amc v8 does i think you can use a block of plate for a ford seem to me like they were alike but maybe uoside down.

 

[kickitandholdit]

well i have a bet with my buddy that a primer bulb from the boat store will work so it looks like i might give it a try for s and giggles. i doubt it will work. my friend works a boat shop so he thinks that priming the mechanical pump and stuff with a bulb will work to get the gas flowing again. i dont think he understands that a pump in working condition will get the gas flowing by its self haha.

so then maybe a block off plate from summit since im passing by the summit store tomorrow. followed by an electric fuel pump. at least with an electric pump i can add a hidden switch for added security i guess.

it might be a while before i can get to tinkering with it because school starts back soon but ill let you know how things work.

thanks for the info guys.

 

[kadar]

I had a Olds engine that did the same thing. I cut a plate out of 1/8" steel and made a gasket and blocked the pump opening and used a stewart & warner electric fuel pump. Wired to the ignition or a kill switch hidden. Saved my battery and starter.

 

[gutthans]

Your best bet IMHO is an electric pump to push fuel from the tank. ANY NON-FI (non-fuel injected) pump will do. BALKAMP or even MR.GASKET have simple cheap units.

On mine, I have a Mr. Gasket mounted at the cross member slightly below the middle of the tank. It goes directly to a CJ5 /16 WIX (silver barrel) filter with the built-in 1/4" return port plumbed back to the top of the tank...don't need a regulator that way.

BTW if you put an inline fuel gauge in the plumbing you can fiddle with placing a tiny restriction into the return line to get exactly the carb pressure you want...I run my Holley this way with a 3/32 ID piece of copper inside the return hose...gives 3.5 lbs. pressure at the carb with my plumbing. (yea, I know Holley says to go 7 lbs., but on a AMC 258 i6 / 4.2l that floods past the needle/seat assembly) unless you have the hi-dollar .093 off-road one.