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post #1 of (permalink) Old 02-14-2002, 10:55 AM
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Jeep dies on sudden movement

I was out pre-running some of the UROC course last night (no, I'm not a competitor) and my CJ has come down with a nasty problem. Whenever I bumped it hard (bounce, drop, etc), the engine would die. To start it, I had to firewall the gas pedal and crank it several seconds. It would finally start sputtering, blow a lot of black crud out the exhaust, then run fine. It seemed to do it most often when pointed skyward (no it's not injected).
Any ideas? Float to high, high fuel pressure, anything?

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post #2 of (permalink) Old 02-14-2002, 01:47 PM
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Re: Jeep dies on sudden movement

It sounds to me like you are having the usual problems with steep angles and carbs. What carb do you have? I have the one barrel, and unless I keep the pedal constant and don't try to return to an idle I can keep it running, but as soon as I let off it loads up, probably from the gas running out of the float bowl. You might try lowering the float a little and see if that helps. The fact that it occurs when you jar it may be from the gas getting sloshed when the Jeep bounces hard.

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post #3 of (permalink) Old 02-14-2002, 02:47 PM
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Re: Jeep dies on sudden movement

The fuel sloshing out of the bowl is the direction I'm thinking. The mystery is that it has never happened before. I run the stock carb and getting vertical has always been a problem, but this happens on small inclines.

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post #4 of (permalink) Old 02-14-2002, 03:04 PM
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Re: Jeep dies on sudden movement

I'm thinking the infamous loose ground problem.

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post #5 of (permalink) Old 02-14-2002, 03:41 PM
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Re: Jeep dies on sudden movement

i would think float as well. if you have the hollow brass float, it may have developed a hole in it. this allows fuel to sit inside the float itself, thus changing the level in the bowl. it would then take more fuel in the bowl to raise it to the cutoff point. i dont know if the other types of floats maybe get pourous over time, and soak up fuel, giving the same result. when you check the float, make sure you take it out and you should be able to tell by how much it weighs whether thats your problem or not.

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post #6 of (permalink) Old 02-14-2002, 04:09 PM
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Re: Jeep dies on sudden movement

No ground problem...just float. A few things to check.
First..Pull the top of the carb off. It's not too hard..and you can do it on the vehicle.
1. Check the float level. The gas level should be apx 1/4" from the top of the bowl...basically, the float should be about level. When I am going up into the mountains, I will sometimes drop my float level down just a fraction to reduce the flooding problem on hills.
2. Make sure that you have the U-shaped shield around the needle valve. It helps reduce the sloshing (sp?).
3. Make sure you have the right fuel filter installed. It contains a bypass (the second smaller outlet tube) to rout the unused gas back to the tank. If you don't have it, then you will have more pressure on the needle and seat than it is designed for.

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post #7 of (permalink) Old 02-14-2002, 04:43 PM
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Re: Jeep dies on sudden movement

Filter's right, but you've given me some good things to check. Thanks.

post #8 of (permalink) Old 02-14-2002, 06:15 PM
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Re: Jeep dies on sudden movement

You might want to read TR's post here.[img]/wwwthreads_images/icons/tongue.gif[/img]

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