78 CJ5 304V8 problems - JeepForum.com
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post #1 of 1 Old 05-27-2019, 10:51 AM Thread Starter
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1978 CJ5 
Join Date: May 2019
Posts: 1
78 CJ5 304V8 problems

Hello, I've grown up working on stuff, but am getting over my head on this project. I have a 78 CJ5 with at 304. Bought it used a few years ago. It ran fine until recently, and I've noticed the following issues.

After I let it sit for 4-5 days, it won't turn over when I crank. Seems like it's starved for fuel. (I replaced fuel pump, fuel filter and fuel tank about 2 years ago). I get it started by pouring gasoline directly into the carburetor and when it starts it blows black gunk out of the exhaust. It will back fire 2-3 times through the carb, and then warm up normally. After about 3-4 minutes, idle is smooth and it runs normally for a 10-15 minutes.

Then after I run an errand or two, it leaves me stranded. It dies usually after about 10-15 minutes of running. The motor is really hot! So I replaced the water/antifreeze and hoses recently, but maybe there's something else going on, like a clogged radiator or water pump issue. I let it cool off and get it started so I can get home.

That's when I started thinking that may be I have a water pump and fuel pump issue. Is it the same mechanism that drives both pumps??? I know I need to tune up the carburetor, and check the timing. What else could cause these issues? sticky fuel? vacuum issue? dirty heads? clogged radiator? all of the above?


1978 CJ5
Spring, Texas
wnimocks is offline  

carburetor , fuel pump , overheating , radiator clogged , water pump

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