My Willys 3A and 3B Community
TECH FAQ SECTIONS => Engine compartment => Topic started by: Marla.the.V35 on May 21, 2022, 04:57:21 PM
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Despite running it a couple of times over a long break, when I take the Jeep for a drive now it has a tendency to die at idle. If I bump the throttle up it'll stay running. I assume this is the idler screw on the carb needs adjustment?
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Hi, that would definately be my first check. It probably drops the revs so far that it simply stalls.
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your idle speed should be about 600 - 650 RPM
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Consider the possibility of trash in the gas. Wouldn't take much to clog a carb port.
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your idle speed should be about 600 - 650 RPM
No tach :) is there some other way to get rpm?
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Harbor Freight photo tach: https://www.harborfreight.com/digital-photo-sensor-tachometer-66632.html (https://www.harborfreight.com/digital-photo-sensor-tachometer-66632.html)
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Consider the possibility of trash in the gas. Wouldn't take much to clog a carb port.
Trash in the gas is certainly a possibility...i just topped the tank for first time in almost a year.. What's the best way to clean this with it still on the jeep (is there a way?)? Carb Cleaner?
I've also got a brand new (looks to be never used) carb that came with the jeep, so perhaps I should consider swapping that one in soon too. Then rebuild the spares.
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If you are running a generator, idle RPM should be between 650 and 700. The generator won't excite and charge below 700. With an alternator, which is self-exciting, 600-650 is okay, but I don't recommend it. Junk in the fuel? A definite possibility. Install a fuel filter. Ceramic is the best, paper the worst. Oh, and if you have been storing Ethanol gas in that tank, seriously consider flushing the entire system because carbs don't process water very well and, as you know, water won't burn. Tachometer? Check eBay for a working, vintage analog Dwell Tachometer. You want one that has 4/6/8 cylinder options. It's inexpensive. Two wires with quick and easy hookup. While you're at it, another diagnostic tool which is absolutely essential is a Diagnostic Vacuum gauge which can also give you fuel pressure readings.
A properly tuned and fed motor will be the result. Find the sweet spot at this link, https://oldjeepcarbs.com/thread/29/time-motor-timing-light (https://oldjeepcarbs.com/thread/29/time-motor-timing-light)
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Well, whatever was happening the other day isn't an issue this morning. Ran the jeep for 6 miles, not a single stall at idle (there was much idling). Only thing I'd done over the weekend was cycle the throttle cable at the carb. I'm guessing if there was trash in a jet, maybe this pressured it loose, or, the throttle cable is sticking and this set it back to position. In any case, I bought some carb cleaner. It could probably use some soon.