need help jeep wants to choke out

need help jeep wants to choke out


Newport News, VA
1979 CJ5 304, T176 w/ Dana 300 twin stick, firecracker red with tan top.
i have a 79 CJ5 304. just replaced the old mc 2100 with a 2150, new coil, plugs and wires. idle sits at about 650-700 rpm. on the way to work this morning it started to die out on me until i let off the pedal started at about 55mph then started doing it at lower speeds. i got to where i was gooing and she idled fine in the parking lot. on the way home no problems. im leaning towards fuel pump (maybe a crack in the diaphram) but i wanted to see if any of yall had other ideas. thanks.
You can do a fuel pressure check by pulling the outlet line from the pump, crank the starter and watch it drain into something like a bucket or better yet hook up a fuel pressure gauge. It should read about 4 p.s.i.
Well I hooked my electric pump up; the one I had from the last mechanical one that failed. Yet this time I didn't make it more than a mile and it actually died. It wouldn't start for about a minute and a half and when it did it it wasn't easy. I'm really baffled by this. Im wondering now if maybe my ignition module got too hot. :censored: this is driving me insane.
It is easy to tell if it's fuel or ignition the next time it dies get right out and take the air cleaner off and look down the carb and pull the throttle back if you see it's squritting gas then it's not a fuel problem it's a ignition problem.
Carolinafan58, when the ignition control module goes bad, you usually will be getting a bad miss in the ignition and the icm will become hot to the touch. Electric fuel pumps need to be installed in a specific way since they push the fuel a lot better then they pull it. This means a siphon has to be created to the pump from the fuel tank. Like mounting the pump at the lowest position possible and closest to the tank as you can, and the fuel lines must have no restrictions like a dirty fuel pickup sock in the tank. Having it wired to recieve full battery voltage at the pump will also help. The in tank fuel pumps will work the best and stay cool that way. A good electric will usually cost well over $100.
If this wasn't happening before you did the work, Id look at the carb.

Generally a coil fails and you're done.

It could be the ignition module, however they usually fail like a switch as well. They work or don't. They may get hot and stop working and then come back like you described.

It sounds like you can manipulate the problem with the gas pedal. Also sounds to me like you're running out of fuel. Maybe you cracked a fuel line or got something in there during the change. You could do what a previous guy said and run it hard until it totally dies, pop the air cleaner and look for a squirt when you open the throttle. Maybe the floats are adjusted wrong and you are draining the bowls.

I'd still run a fuel pressure test to see whats happening when it fails. Hook one up and tape it to the wiper so you can watch it while your driving.
well she is on the road again. All the stuff i replaced and it was rust in the gas tank. 8 years ago i put it in brand new. I guess that shows us how stupid it is to put corn in our fuel...but anyways its just a testament to the 304 because i cant believe it was running at all when i saw the inside of the tank. thanks for the help guys.:chug:
good job!
Glad to hear you found what was wrong and it's on the road again.

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