L134 Won't Idle Without Choke

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   Hi Guys, I've never posted here but have been following the page for several months. I have spent many hours researching on this page and others trying to find a solution to my problem. I'm not one to jump in asking questions until I've pretty much exhausted most resources. I realize the subject of this post has been covered many times so please bear with me.
My L134 in a CJ2A that I'm restoring has been completely rebuilt. I can't get it to idle below 850 rpm and only with the choke mostly closed. I've always suspected a vacuum leak but haven't been able to find one. I've tried every suggestion on these pages except the possibility of a cracked intake manifold. I'm about ready for that but thought I'd ask if anyone knows anything else I can try. Here is what I have done:

Compression is 108 lbs +/- 1 across the 4 cylinders.
Vacuum is fluctuating around 14 +/- 1.
I've tried 4 different carbs, one recently rebuilt by Scout Pilot. Another one that I installed without opening then later rebuilding it with a KaiserWillys kit. A third and fourth one that I just installed as is.
I've verified the idle passages are open on each carb. 
I've pulled and cleaned and measured every jet and passage.
I've changed diffuser gaskets 2 or 3 times and have crushed the copper sleeves.
I've used the carb cleaner and propane methods of tracing leaks with none found.
I've tried tweaking the metering rod up and down.
I've verified timing set at 5 degrees.
I've readjusted the valves going over them several time to verify .016 clearance.
Points set at .020, dwell = 41.
Plugs set at .030. Engine running very rich, plugs turn black quickly.

One thing that might be a clue to someone: when I start the engine cold, it runs very rough for the first minute or so, then smooths out. Like one cylinder isn't firing.

No matter what I've done, the result is always the same. I'm about at wits end. I ordered new manifold gaskets today so I guess thats next unless someone has a better idea. I have a couple more manifold sets so I'll try to verify at least one of them doesn't have any leaks. 

Any suggestions will be greatly appreciated.

Thanks,

Larry...

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Lhead Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 02 Mar. 2018 Location: Valley Ctr CA Status: Offline Points: 166	Post Options Post Reply Quote Lhead Report Post Thanks(0) Quote Reply Topic: L134 Won't Idle Without Choke Posted: 17 Sep. 2018 at 9:07pm
	Hi Guys, I've never posted here but have been following the page for several months. I have spent many hours researching on this page and others trying to find a solution to my problem. I'm not one to jump in asking questions until I've pretty much exhausted most resources. I realize the subject of this post has been covered many times so please bear with me. My L134 in a CJ2A that I'm restoring has been completely rebuilt. I can't get it to idle below 850 rpm and only with the choke mostly closed. I've always suspected a vacuum leak but haven't been able to find one. I've tried every suggestion on these pages except the possibility of a cracked intake manifold. I'm about ready for that but thought I'd ask if anyone knows anything else I can try. Here is what I have done: Compression is 108 lbs +/- 1 across the 4 cylinders. Vacuum is fluctuating around 14 +/- 1. I've tried 4 different carbs, one recently rebuilt by Scout Pilot. Another one that I installed without opening then later rebuilding it with a KaiserWillys kit. A third and fourth one that I just installed as is. I've verified the idle passages are open on each carb. I've pulled and cleaned and measured every jet and passage. I've changed diffuser gaskets 2 or 3 times and have crushed the copper sleeves. I've used the carb cleaner and propane methods of tracing leaks with none found. I've tried tweaking the metering rod up and down. I've verified timing set at 5 degrees. I've readjusted the valves going over them several time to verify .016 clearance. Points set at .020, dwell = 41. Plugs set at .030. Engine running very rich, plugs turn black quickly. One thing that might be a clue to someone: when I start the engine cold, it runs very rough for the first minute or so, then smooths out. Like one cylinder isn't firing. No matter what I've done, the result is always the same. I'm about at wits end. I ordered new manifold gaskets today so I guess thats next unless someone has a better idea. I have a couple more manifold sets so I'll try to verify at least one of them doesn't have any leaks. Any suggestions will be greatly appreciated. Thanks, Larry...
	Larry 46 CJ2A L134 33 Ford Merc Flathead

mbullism Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member x 4 Joined: 29 May 2015 Location: MA Status: Online Points: 4783	Post Options Post Reply Quote mbullism Report Post Thanks(0) Quote Reply Posted: 17 Sep. 2018 at 9:25pm
	couple things come quickly to mind... 14 inches is pretty low vacuum, and it should be steady... kinda odd you have such decent compression timing will likely be closer to 8 BTDC using pump regular, given the ethanol content you never mentioned wiper motor it could be a fuel supply issue, as in sucking air through the lines and not delivering without the choke... (I'm chasing a similar demon, though I only need a small amount of choke...and I have 19+ inches of steady vacuum) Oh, and welcome aboard Edited by mbullism - 17 Sep. 2018 at 9:30pm
	Those who do not learn from history are doomed to repeat it... Welcome to 1930's Germany

russnj Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Webmaster Joined: 20 July 2005 Location: W. Windsor, NJ Status: Offline Points: 3943	Post Options Post Reply Quote russnj Report Post Thanks(0) Quote Reply Posted: 17 Sep. 2018 at 9:28pm
	Post some pictures of your setup, it might help figure it out.
	43 MB, 48 CJ2A, 50 CJ3A, 55 M38A1, 56 CJ5, 79 M151A2, M100 ,65 M416

Stev Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member Joined: 27 July 2016 Location: Cincinnati Status: Offline Points: 2384	Post Options Post Reply Quote Stev Report Post Thanks(0) Quote Reply Posted: 17 Sep. 2018 at 9:35pm
	Lhead, Some shots is the dark to try: 1. Is the vacuum hose to the windshield wiper cracked or not hooked up and air is getting in there? Replace the hose with a good section and put a golf tee in the hose to plug it - see if that changes your air leak. 2. Is your PVC valve stuck - Unscrew it from the intake manifold and take it apart. Clean the internal parts. 3. When installing intake and exhaust manifolds they are not supposed to be bolted to each other until after they are snugged against the gasket. Then they tighten them to each other. 4. Could be a bad plug, plug wire, bad bushing in the distributor. It will most probably be something simple.
	Stev 1946 CJ2A Trail Jeep (The Saint), 1948 CJ2A Lefty Restored

a4cj2a77 Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member Joined: 03 Sep. 2012 Location: Seal Beach Ca. Status: Offline Points: 566	Post Options Post Reply Quote a4cj2a77 Report Post Thanks(0) Quote Reply Posted: 17 Sep. 2018 at 9:43pm
	i had issues with diffuser gasket on mine as well because of the copper sleeves. sure sounds like a vac leak to me. I would think if you have a carb from scout pilot and you haven't changed settings on it, that would be the carb to stick with to figure out your issue. We use a smoke machine to trace leaks visually, but propane should work. Phil

Lhead Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 02 Mar. 2018 Location: Valley Ctr CA Status: Offline Points: 166	Post Options Post Reply Quote Lhead Report Post Thanks(0) Quote Reply Posted: 17 Sep. 2018 at 10:14pm
	Thanks for the quick replies. I guess i left off a couple important points earlier. First, I don't have wipers (yet) and the vacuum port on the manifold between the carb and the firewall is blocked off as is the one at the base of the carb. I've removed, cleaned, even eliminated the PCV valve. No change. Distributor has been rebuilt and all components (points, condenser, rotor, cap, wires, and plugs) are new. Fuel pump is new and has about 4 psi pressure. One possible point might be that there are two glass strainers, one upside down on the fuel pump, the other at the carb. Maybe too much restriction? It fills the carb bowl up pretty fast so I doubt that is an issue. Plus it seems to run at higher RPM fine, just won't idle right. The setup is basically stock except 12v upgrade. See photos. One note, I have been doing all the testing so far without the air cleaner installed. Could that make any difference? I'll post a couple pictures as soon as I can get them to load on my computer from my phone. I agree it is most likely something simple but I'm simpled out! Ha Ha! Thanks, Larry...
	Larry 46 CJ2A L134 33 Ford Merc Flathead

SteveBonny Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 15 Sep. 2018 Location: Waterloo Iowa Status: Offline Points: 103	Post Options Post Reply Quote SteveBonny Report Post Thanks(0) Quote Reply Posted: 17 Sep. 2018 at 10:17pm
	I've had similar symptoms with just a plugged fuel filter - needs the choke to suck enough fuel. Does it run OK with power, is it just an idle issue? If it won't run at power either you might check through the rest of the fuel system ahead of the carb - bad pump, plugged fuel filter plugged/ crimped fuel line etc.
	47 CJ2A

Lhead Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 02 Mar. 2018 Location: Valley Ctr CA Status: Offline Points: 166	Post Options Post Reply Quote Lhead Report Post Thanks(0) Quote Reply Posted: 17 Sep. 2018 at 10:30pm
	Here are a couple of pictures of the engine bay. The picture looks too big in the preview. If it comes out that way, I'll try to figure out how to shrink it. Larry...
	Larry 46 CJ2A L134 33 Ford Merc Flathead

ndnchf Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member x 2 Joined: 22 Sep. 2017 Location: Virginia Status: Offline Points: 2177	Post Options Post Reply Quote ndnchf Report Post Thanks(0) Quote Reply Posted: 17 Sep. 2018 at 10:41pm
	If you need 2 fuel filters and the glass bowl screen to get clean gas, maybe its time to treat yourself to a new gas tank. They are not very expensive. All that filtering creates flow resistance that adds up snd could be contributing to your problem.
	1948 CJ2A - It goes nowhere fast, but anywhere slow.

Lhead Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 02 Mar. 2018 Location: Valley Ctr CA Status: Offline Points: 166	Post Options Post Reply Quote Lhead Report Post Thanks(0) Quote Reply Posted: 17 Sep. 2018 at 10:46pm
	Well, it is a new tank but it has been sitting around here for a few years so I figured it might have spiders and other creatures looking for a home that needed filtering. Point well taken though, I'll bypass all but one to see if that helps.

SteveBonny Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 15 Sep. 2018 Location: Waterloo Iowa Status: Offline Points: 103	Post Options Post Reply Quote SteveBonny Report Post Thanks(0) Quote Reply Posted: 17 Sep. 2018 at 11:19pm
	Looks too clean to me. I think you need more dirt and grime to help plug up all the gasket leaks Sorry, not being much help here.
	47 CJ2A

SteveBonny Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 15 Sep. 2018 Location: Waterloo Iowa Status: Offline Points: 103	Post Options Post Reply Quote SteveBonny Report Post Thanks(0) Quote Reply Posted: 18 Sep. 2018 at 12:31am
	Back on the fuel side, if you have the right T fitting you could T in a fuel pressure gauge right at the carb inlet and test your pump as well as all the fuel lines/filters etc. It should get about 1-2psi I think. My example of similar symptoms was actually a small inlet screen right at the inlet of the carb that was plugged, but if you have changed carbs it wont be this. A story just for fun..... many years ago I worked for about a week with a group of about 4 other engineers trying to figure out why a bunch of 4wd loaders wouldn't start after they had been loaded on the shipping truck right out of the factory. They would drive off to destination but couldn't be unloaded from the truck because they wouldn't start. After about a week of trying everything, we were at our wits end when a marketing dude stopped over and asked if there was any fuel in the tank........ It turned out that the fuel level gauge calibration was wrong and showing 1/4 tank when they were empty. The tank designers had also removed a tank baffle to save money. Whenever they ran up the truck ramp they would suck air.........
	47 CJ2A

athawk11 Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 18 Jan. 2012 Location: Arvada,Colorado Status: Offline Points: 4151	Post Options Post Reply Quote athawk11 Report Post Thanks(0) Quote Reply Posted: 18 Sep. 2018 at 1:28am
	At sea level, you should be able to acheive 21Hg of steady vacuum on an engine. I would focus on this issue. Are you sure you don't have a sticky valve? I think trying a different intake manifold is a good idea. We had a member at the 3A Page with an internal crack on his intake manifold. He was having similar issues. He pulled the intake, then poured water through it. The leak was in the area where the intake manifold bolts to the exhaust manifold. The leak never showed up with the starter fluid/propane tests.
	1- 1946 CJ2A 2- 1949 CJ3A

Lhead Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 02 Mar. 2018 Location: Valley Ctr CA Status: Offline Points: 166	Post Options Post Reply Quote Lhead Report Post Thanks(0) Quote Reply Posted: 18 Sep. 2018 at 1:51am
	I eliminated two filters just leaving the screen/bowl on top of the fuel pump. Should have been a 5 minute job but just to prove the old adage, it doesn't matter how many fittings you have, you won't have the one you need. So a trip to the hardware store. No difference. But I'm not convinced now that it isn't a fuel delivery problem. I'm draining the tank (yes it had fuel in it) and I'm going to rig a temporary tank. I also have another fuel pump to try. If those fail, I'm off to intake manifold land. Problem is that I ordered the gaskets today and KaiserWillys takes a week to get here. Oh well, I guess I can get my windshield finished and in place and finish the wiring while I'm waiting. I don't want to put the fenders on until the engine is dialed in. Larry...

ralf Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member x 2 Joined: 06 May 2008 Location: Fayetteville WV Status: Offline Points: 4861	Post Options Post Reply Quote ralf Report Post Thanks(0) Quote Reply Posted: 18 Sep. 2018 at 1:52am
	See, Scout Pilot. I am too old to learn to understand carbs. I want to drive my Jeep, not work on it. Same with my Piper Cub and the Stromberg Carb. I want to fly, not fiddle with something I don't understand. Of course there is more of a down side (pun intended) to a Stromberg. Ralph
	1947 CJ2A 1948 CJ2A 1953 Ford NAA Golden Jubilee Tractor 1941 J-3 Cub 1957 Farmall Cub Low Boy tractor 1942 Clarktor WW2 tug

Lhead Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 02 Mar. 2018 Location: Valley Ctr CA Status: Offline Points: 166	Post Options Post Reply Quote Lhead Report Post Thanks(0) Quote Reply Posted: 18 Sep. 2018 at 1:55am
	I forgot to ask a question: with the engine running, should the glass bowl on top of the fuel pump fill up? Mine doesn't. I can seen fuel running through it but it doesn't fill up. I did check fuel pressure with a "T" and I had about 4 psi. Larry...

ndnchf Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member x 2 Joined: 22 Sep. 2017 Location: Virginia Status: Offline Points: 2177	Post Options Post Reply Quote ndnchf Report Post Thanks(0) Quote Reply Posted: 18 Sep. 2018 at 2:14am
	Mine fills up and stays filled when running.
	1948 CJ2A - It goes nowhere fast, but anywhere slow.

mbullism Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member x 4 Joined: 29 May 2015 Location: MA Status: Online Points: 4783	Post Options Post Reply Quote mbullism Report Post Thanks(0) Quote Reply Posted: 18 Sep. 2018 at 2:46am
	It should be all but full if not full. Are all your rubber to tubing connections barbed?... flares doubled and not too big?
	Those who do not learn from history are doomed to repeat it... Welcome to 1930's Germany