Carb too Lean?

[73 CJ5]

I have a 73 CJ5 with the AMC 258 i6 / 4.2l and a single barrel carter carburetor. My jeep is cutting out when I accelerate but idles and runs fine at consistent speed, would this mean that I am running to lean?

Any help is always appreciated...

 

[priceg]

Check to see if your accelerator pump is operational.

 

[73 CJ5]

I will check the accelerator pump again. I rebuilt the carb and it continues to do the same thing. I also will check to make sure I am getting the fuel shot while accelerating, i forget the reccomended specs for the fuel mix adjustment but have tried them both, could it simply be that I need to increase the mix past reccomended?

Funny how the more you fight with something the more second guessing comes into play...

 

[fzsk4p]

The mixture screws only control the fuel/air mixture at idle.

Look for a vacuum leak that would be on a ported vacuum source. A ported source draws no vacuum at idle/low throttle openings. So it would idle fine and at cruise the engine may be drawing enough vacuum that you do not feel the problem. But on acceleration, when the vacuum drops the engine runs lean.

 

[IOPort51]

If you have an EGR valve check the vacuum line going to it, the line is hooked to the ported vacuum and look for vacuum leaks every where.

 

[fzsk4p]

If you have an EGR valve check the vacuum line going to it, the line is hooked to the ported vacuum and look for vacuum leaks every where.

Good point IOPort51. The EGR can be a nasty bugger.

 

[73 CJ5]

Thanks for all the suggestions, I will be checking the vaccum tonight and if no leaks I plan on double checking the accelerator pump. Will let you all know tomorrow. I do know that there is no EGR. If I cannot fis it tonight I will post pics on the exact set up as I am missing several lines.

 

[73 CJ5]

replaced a few vaccum lines going to the carb and we are accelerating like a champ! I created a new problem however so I am going to start a new thread for that. Thanks a ton... I have been riding the motorcycle to work in 30 degree weather so a warm Jeep will be a welcomed change.

 

[73CJ]

Nobody has suggested to check the timing.

My stock carb would cough when real cold. Then run fine at high rpm. How does yours run at high speed?

Is it in 3rd gear only? ( with a T-14 ) 73s had a switch in 3rd gear that reduced ignition advance. Not required.

A vacuum leak usually causes it to idle real low and sometimes die idling.