Carburetor troubleshoot/Help!
applegrower
Jeeper
- Posts
- 10
- Thanks
- 0
- Location
- Central NY
- Vehicle(s)
- 1984 CJ7, AMC 150ci 4 cyl, 4 speed, Dana 300, AMC 20. Stock.
Hi All,
First post here, go easy... In desperate need of some real carb gurus!
Relatively new jeeper. Bought my first CJ about a year ago, made some minor repairs and improvements and drove it all last summer! Put it in storage,(and moved to NY over the winter) and took it out a month ago. Started right up and fine getting it on/off the trailer, then would not run right after I got it home. Here's my issue:
It seemes to be running VERY lean; would fire right up and sometimes idle great when cold, but as soon as the choke opened up it would die and not start unless I was on the throttle. Reset to factory settings and that did nothing, and actually made it worse to the point where it would not run at all. It would not run unless the idle speed screw was cranked way in.
I checked for vacuum leaks, sprayed the
out of it with carb cleaner, and tried to tune it with the idle mix for a solid 2 weeks before deciding to rebuild the carburetor.
Last week I rebuilt the carb, replacing everything in the kit and then some. Everything looked good except for being extremely dirty; the power valve diaphragm (NOT the accel pump diaphragm) looked to have a small tear in it and was very worn, so that was replaced as well.
Put the carb back on, and the exact same thing is still happening. First crank after I bolted on the rebuilt carb and it fired right up, ran and idled the best it EVER has, so I let it tractor on factory settings. (Idle Speed = 1 crank in after contact w/ linkage, Idle Mix = 2.5 turns out.) As soon as the electric choke opened up it died. Now it will not start unless my foot is on the accel. Anybody have any idea as to what my issue is?
THINGS TO NOTE:
1. The carb is NOT a factory Carter. It is a Weber DGV 2 barrel electric choke that the PO installed. It is a true original Weber, and the rebuild kit I bought was from Redline. I believe it is jetted properly.
2. Was running very rough when I bought it last summer. PO had it tuned totally wrong. I messed with the idle mix screw and made it better, but it still seemed to stumble/choke if I gave it a lot of throttle while going down the road (i.e. stepping on it in 4th gear.) mimicing a lean condition. It would not run unless the Idle Speed screw was turned waaay in (3-4 turns) and I left it that way for the end of the season. I did a full tune up when I purchased it, which helped a lot also.
3. Since reinstalling the carb last week I have re-checked:
- float level (correct - 35mm/51mm for plastic float)
- clogged jets (idle jet was clogged on reinstall but everything is now clear.)
- proper gasket seating
- linkage binding. - seems to "snap" fine, linkages installed correctly.
4. I have checked for vacuum leaks by eye but cannot keep it running to use carb cleaner to spray mounting gaskets etc. There were two massive ports on the intake manifold that were open. I plugged those, tried it, no luck. (Note: those ports have always been open since I've owned the jeep though.)
5. I am assuming that fuel pressure is good, although I should not. I am assuming this because I can still floor it and it runs great.
Sorry for the long winded post; please offer any help or advice if I am missing something very obvious. As the weather is getting nicer I am getting very antsy to get her out on the road!
Thank You!
First post here, go easy... In desperate need of some real carb gurus!
Relatively new jeeper. Bought my first CJ about a year ago, made some minor repairs and improvements and drove it all last summer! Put it in storage,(and moved to NY over the winter) and took it out a month ago. Started right up and fine getting it on/off the trailer, then would not run right after I got it home. Here's my issue:
It seemes to be running VERY lean; would fire right up and sometimes idle great when cold, but as soon as the choke opened up it would die and not start unless I was on the throttle. Reset to factory settings and that did nothing, and actually made it worse to the point where it would not run at all. It would not run unless the idle speed screw was cranked way in.
I checked for vacuum leaks, sprayed the

Last week I rebuilt the carb, replacing everything in the kit and then some. Everything looked good except for being extremely dirty; the power valve diaphragm (NOT the accel pump diaphragm) looked to have a small tear in it and was very worn, so that was replaced as well.
Put the carb back on, and the exact same thing is still happening. First crank after I bolted on the rebuilt carb and it fired right up, ran and idled the best it EVER has, so I let it tractor on factory settings. (Idle Speed = 1 crank in after contact w/ linkage, Idle Mix = 2.5 turns out.) As soon as the electric choke opened up it died. Now it will not start unless my foot is on the accel. Anybody have any idea as to what my issue is?
THINGS TO NOTE:
1. The carb is NOT a factory Carter. It is a Weber DGV 2 barrel electric choke that the PO installed. It is a true original Weber, and the rebuild kit I bought was from Redline. I believe it is jetted properly.
2. Was running very rough when I bought it last summer. PO had it tuned totally wrong. I messed with the idle mix screw and made it better, but it still seemed to stumble/choke if I gave it a lot of throttle while going down the road (i.e. stepping on it in 4th gear.) mimicing a lean condition. It would not run unless the Idle Speed screw was turned waaay in (3-4 turns) and I left it that way for the end of the season. I did a full tune up when I purchased it, which helped a lot also.
3. Since reinstalling the carb last week I have re-checked:
- float level (correct - 35mm/51mm for plastic float)
- clogged jets (idle jet was clogged on reinstall but everything is now clear.)
- proper gasket seating
- linkage binding. - seems to "snap" fine, linkages installed correctly.
4. I have checked for vacuum leaks by eye but cannot keep it running to use carb cleaner to spray mounting gaskets etc. There were two massive ports on the intake manifold that were open. I plugged those, tried it, no luck. (Note: those ports have always been open since I've owned the jeep though.)
5. I am assuming that fuel pressure is good, although I should not. I am assuming this because I can still floor it and it runs great.
Sorry for the long winded post; please offer any help or advice if I am missing something very obvious. As the weather is getting nicer I am getting very antsy to get her out on the road!
Thank You!