Full Size Jeep Network

I think this is just a “normal” issue, but wanted to ask in case there might be something else going on.

My jtruck sits a lot, especially when the weather is bad (raining) I might not start or drive it for 2 or 3 weeks. It has a 6mo old Holley on it, fast idle is set at 1500rpm and it drops to about 550 when the choke comes off. Idle is quiet and smooth.

I’ve noticed that starting from stop almost kills it the first couple times. It’s like no gas is getting to the carb but step on the clutch and it goes back to a nice idle.

Last night I probably rushed my departure, made it to the end of my street fine, but pulled out into traffic and nothing. Step on the gas to take off and it almost acted like a kill switch. Stepped on the clutch quick and it recovered so I was able to limp it to the side of the road where I let it idle for a few more minutes. Then took off again and had no more issues.

So is this just simply a symptom of a cold carb’d motor or is something else going on? It runs and drives great otherwise and when I let it warmup for 10mins or better I don’t experience what I did last night. It just seemed so dramatic I guess.


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Sounds like a bad choke adjustment or your choke is not working at all. (despite the fast idle cam working as you described)

I’ve fiddled with the choke some and maybe I don’t have it right yet. On first startup it idles high for a few seconds then kinda bogs down for maybe 15s until the choke starts to open. Then the idle goes up quickly to about 1500 where I have it set. As soon as blip the throttle tho it drops to 550 and stays there.


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You have the factory 2V Holley or an aftermarket Holley? Do you have a manual choke or electric? The Holley electric choke kit should fit the factory Holley carb too. In my experience, the external choke parts are interchangeable between models. https://www.holley.com/products/fuel_sy ... rts/45-223 There is also a kit that uses external vacuum. Your carburetor may or may not have an internal passage connecting the choke cover to engine vacuum.

If you have a manual choke, the fast idle stop should be riding up on the cam if the flap is closed, even part way. The electric choke is similar.

It’s an aftermarket Holley 80457, 4bbl, 600cfm with electric choke.


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If the choke is backing off too fast, Holley sells another part https://www.holley.com/products/fuel_sy ... rts/45-267 that slows the coil unwinding as long as the manifold is cold. Likely just a negative-type thermistor in a fancy package...

Doesn't Holley provide adjustment information for the choke? It looks like the Holley electric choke has a stepped cam, similar to the Motorcraft carburetor. With that cam, the fast idle should not fall off until the throttle is depressed. If the fast idle falls off too fast, that means that the choke spring is unwinding too quickly, before the engine is fully warm. Have you tried adjusting the fast idle stop to see if you can keep the idle up longer? Also, too-fast unwinding will lean out the mixture before the manifold is warm enough to keep gas from condensing on the cold manifold.

Thanks tgreese for all the thoughtful responses. I have adjusted the choke according to Holley’s instructions but I may not have it just right yet.

The fast idle is staying on and drops when I hit the gas like it should. I haven’t actually let it idle long enough for the idle to come down on its own. I usually just bump the throttle once I notice the temp gauge start to move.


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If your air filter has the provision for hot air from the exhaust manifold make sure it is hooked up. Not sure if the 327 had this but it makes a HUGE difference on my 350.