Jeep Wrangler Forum banner
  • Hey everyone! Enter your ride HERE to be a part of JUNE's Ride of the Month Challenge!

1 - 9 of 9 Posts

·
Registered
Joined
·
71 Posts
Discussion Starter · #1 ·
So I'm not that experienced with carbs at all so thanks for the help. I got a 4.2 with the stock carb. Its a 90. Whenever I start it cold for the first time in the morning i need to give it gas for it to start. If I dont it catches then dies. On top of that. The choke gets stuck at about 2200rpm and stays on unless I manually turn it off. Once it warms up it continues to idle like crap but the choke doesn't get stuck. On cool mornings. It stalls out untill it warms up some. I haven't done anything to the jeeps motor yet. I'm planning on buying a Weber down the road. Any help?? Thannks
 

·
Registered
Joined
·
1,738 Posts
"Giving it gas" before starting "sets" the choke. This was SOP before fuel injection and electronics everything.

The choke idle screw needs to be adjusted down a bit until you are idling about12-1500.

Adjusting the warm idle should clear up your rough idle when warm.

Failing THESE fixes... possible float issue.....gasket issue.....needle valve......TB warpage...
 

·
Registered
Joined
·
71 Posts
Discussion Starter · #3 ·
"Giving it gas" before starting "sets" the choke. This was SOP before fuel injection and electronics everything.

The choke idle screw needs to be adjusted down a bit until you are idling about12-1500.

Adjusting the warm idle should clear up your rough idle when warm.

Failing THESE fixes... possible float issue.....gasket issue.....needle valve......TB warpage...
Thanks for the reply man. Do you know where the warm idle adjust is?
 

·
Registered
Joined
·
1,738 Posts
Nope......would have to see it in action to tell you.....
 

·
Registered
Joined
·
8,968 Posts
There is an idle set screw on the driver's side of the carb at the linkage. On a hot engine in park/neutral you should be at approx. 700-800 rpm's. Closer to 800 would be better for these carbs. When cold to start, pump it twice and start it with your foot off of the pedal. It should go to a high idle. The top idle cold will be between 1800 and 2200 rpm. After 30 seconds to a minute it should kick down to 1200-1500, once you tap the pedal. After another minute or two it should kick down again to approx. 1000 rpm, after you tap the pedal again. When warm/hot it should idle at 700-800 rpm. You can clean the carb and linkage with carb and choke cleaner. That might help until you replace the carb. To start it warm/hot, as you're cranking hold the pedal down about 1/2 to 3/4 until it starts. That start procedure is in the owners manual also. You need to give it some gas on a warm/hot start, unlike fuel injection.
 

·
Registered
Joined
·
71 Posts
Discussion Starter · #6 ·
There is an idle set screw on the driver's side of the carb at the linkage. On a hot engine in park/neutral you should be at approx. 700-800 rpm's. Closer to 800 would be better for these carbs. When cold to start, pump it twice and start it with your foot off of the pedal. It should go to a high idle. The top idle cold will be between 1800 and 2200 rpm. After 30 seconds to a minute it should kick down to 1200-1500, once you tap the pedal. After another minute or two it should kick down again to approx. 1000 rpm, after you tap the pedal again. When warm/hot it should idle at 700-800 rpm. You can clean the carb and linkage with carb and choke cleaner. That might help until you replace the carb. To start it warm/hot, as you're cranking hold the pedal down about 1/2 to 3/4 until it starts. That start procedure is in the owners manual also. You need to give it some gas on a warm/hot start, unlike fuel injection.
I appreciate the help man! I'm definitely going to check it out. If the choke continues to not shut off by its self what should I look for?
 

·
Registered
Joined
·
8,968 Posts
I appreciate the help man! I'm definitely going to check it out. If the choke continues to not shut off by its self what should I look for?
If it's activating, meaning that it goes to a high idle when you set it, your auto choke housing spring I would say is operating correctly. Pull the air cleaner on a cold engine and set the choke by hand, pulling back on the accelerator linkage, and see if anything is hanging up. Your carb plate should be almost closed. I would spray all of these areas with carb and choke cleaner. Then start it. If you're on a high idle you're fine. Give it a minute or less and manually pull back on the throttle linkage as if you were tapping the accelerator and see if the idle drops down. You should be able to tell if the linkage is free or hanging up. If I'm understanding you correctly, the choke won't shut off by itself. You have to press/tap the accelerator pedal to drop the idle on a cold engine.
 

·
Registered
Joined
·
71 Posts
Discussion Starter · #8 ·
Ill mess around with that tomorrow. As of right now I adjusted the idle so its idleing better and around 850 warm. I also adjusted the choke and it seems to be staying at around 1800. But whenever I tap the pedal to take it off it doesn't. I will try cleaning and trouble shooting like you said tomorrow
 

·
Registered
Joined
·
71 Posts
Discussion Starter · #9 ·
If it's activating, meaning that it goes to a high idle when you set it, your auto choke housing spring I would say is operating correctly. Pull the air cleaner on a cold engine and set the choke by hand, pulling back on the accelerator linkage, and see if anything is hanging up. Your carb plate should be almost closed. I would spray all of these areas with carb and choke cleaner. Then start it. If you're on a high idle you're fine. Give it a minute or less and manually pull back on the throttle linkage as if you were tapping the accelerator and see if the idle drops down. You should be able to tell if the linkage is free or hanging up. If I'm understanding you correctly, the choke won't shut off by itself. You have to press/tap the accelerator pedal to drop the idle on a cold engine.
↑↑↑↑
 
1 - 9 of 9 Posts
Top