Engine idles but won't rev

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cdday63
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Engine idles but won't rev

Post by cdday63 » Sun Jan 21, 2018 7:16 am

I have a '53 3B that is mostly stock. It sat for about a year and a half while I eventually replaced the generator with a starter and had the starter rebuilt. So about two months ago when I tried to start it would only run for a few seconds when gas was put in the carb. I replaced the electric fuel pump, checked the fuel lines, and cleaned out the fuel tank. It would then run for about a minute until it quit. I had the carb(solex) cleaned out and replaced the inline fuel filter. It now idles beautifully but as I stand by the engine compartment and run the throttle it sounds like it chokes itself out and quits. It sounds like a gas powered weed eater when you shut it down. The oil bath sounds like a jet engine. It still has oil in it and the tube to the carb is clear. It idles great whether the oil bath is hooked up to the carb or not. Please help.


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Re: Engine idles but won't rev

Post by artificer » Sun Jan 21, 2018 8:57 am

See if the engine will run properly with the bowl off the oil bath air cleaner.
If so the bowl is overfilled.
John GIBBINS Member Institute of Automotive Mechanical Engineers [Ret], ASE Master Medium/Heavy Truck & Auto Technician USA -2002 Licensed Motor Mech NSW MVIC 49593 Current 2015
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Understand how system parts interact with one another. GOOD parts can then be established & the NOT GOOD problem/s part/s isolated for repair or replacement.

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Re: Engine idles but won't rev

Post by cdday63 » Sun Jan 21, 2018 6:52 pm

Ok. Thanks.

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Re: Engine idles but won't rev

Post by Wolfman » Mon Jan 22, 2018 4:58 am

Last sentence - It idles fine with the oil bath hooked up or not.
So does it take throttle with the oil bath disconnected ??
When I got my CJ, it had set in a farmers tool shed for a long time.
One thing I found, beside a blown head gasket, was a mouse critter and I am guessing, his whole family, had taken up residents in the top of the air cleaner. On top of the wire mesh. What a mess.
"Oil bath sounds like a jet engine". Might be a good place to look.
If it won't take throttle with the oil bath disconnected, I would be taking another look at the carb.
From there it gets worse. May be a sticking valve or something along that line. It has set for a while.
I assume ( there's that word ) you have checked the points and plugs. ??
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Peterdodge6volt
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Re: Engine idles but won't rev

Post by Peterdodge6volt » Wed Jan 24, 2018 2:25 pm

Mmm I had this before on my restored and unrestored jeep.
Did you check if there's is no air leak on the carby and manifolds gaskets. Most people and friends in Australia call it carby flat or manifold flat. It means one of them was not machined properly or the block manifold.
If none of them has air leak then it's your carby, will need rebuild or cleaning or replace,

The another thing can do that is condensers or points is worn out or full of dirty sparks dust.
Try run the engine but don't rev leave it running normal with out rev for 1 minutes and touch the coil if it's very hot be careful.
If it's is hot then change the condenser.


Cheers Peter

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Re: Engine idles but won't rev

Post by JMZ421 » Thu Jan 25, 2018 7:06 am

Maybe ckeck the points to make sure rubbing block is not worn and lubed correctly. My M38 was doing something like this and my points were the issue. Replaced points, lubed rubbing block, reset timing and she revved up. Just a thought John

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Re: Engine idles but won't rev

Post by Bart1015 » Thu Jan 25, 2018 11:24 am

Its timing or fuel delivery.

This could be due to adjustment, condenser or other mechanical issues. Signaling out each system will be the fastest and easiest way to figure it out.

I would do the following:

See if someone close to you would be willing to put their carb on your jeep. You need to make sure the carb you put on is a good unit.

If the "known" good carb acts the same way, check for leaks around the intake manafold/heat riser. I use an unlit propane torch. I turn on the torch and direct the gas to right where all the parts bolt together. If the idle get higher as you pass by the joints, you have a leak.

If the problum is not fuel, then try to install a "Known" good dist. assembly and see how it runs.

If still the same, swap out the coil for a "Known" good unit. I had a M151 that would die out above idle and it turned out to be the coil.

Just my .02

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Re: Engine idles but won't rev

Post by cdday63 » Thu Jan 25, 2018 6:19 pm

Thanks


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