Intermittent Stalling Issue

Not sure what is happening here. Jeep seems to be running fine but anytime I have it out for long, it will start dieing on me. It always seems to be during acceleration, it just looses all power (really feels like it is out of gas) but it will start right back (sometimes just roll starting is enough) the strange thing is that it almost always happens late in the acceleration (shifting from 2nd to 3rd or just after getting into third or during a long pull in 2nd) it does not happen all the time but seems to get worse the longer I have been driving it.


The engine revs up fine and seems to be responsive and to have plenty of power off the line (for a f-head). I cant seem to make it happen just sitting in the driveway and revving the engine. That said, I have not tried to just keep it revved up for an extended time.


My guess is some kind of carb (float sticking when hot??) issue but figured I would check with the pros around here before I attack anything.

FYI 1960 CJ5 Fhead, elect ignition, new sparkplugs and wires, basically stock I think it is the SOLEX replacement carb and not the stock Carter.

 

The first two things I would check based on those symptoms is an incorrect float level setting and/or weak fuel pump. It sounds like under heavy demand for fuel, you are running out. The float bowl acts as a fuel "buffer" of sorts, making sure there is enough fuel in high-demand scenarios where the fuel pump alone might not deliver enough fast enough. Float level set too low and you will suck the bowl empty before the pump can catch up.

Also, if the float level is set correctly, but the pump is weak, same symptoms. It will run okay for a bit until the demand depletes the reserve in the float bowl and the pump can't keep up. Obviously many other possibilities, vapor lock, etc., but that is where I would start.

 

I am not a specialist, but I have a Hurricane with a Solex. Years ago I had some difficulties, I found on this forum the way to clean my carb, it takes time and must be done carefully. I also put new spark plugs. And since this time all works perfectly. Nothing complex, clean first. Then see what happens.

 

fuel filter may need replacing

 

Precisely this. Under acceleration/load it is not flowing enough gas.

 

filter is new, replaced it when I replaced all the fuel lines.

 

Dang...i hoped it was that simple

 

Do solexes have an internal filter? Checked the pick-up in the tank? Water in carb bowl?

Solexes are known to have venturi icing issues under certain conditions.

 

didn't look at the pickup in the tank as the screws that hold it in will not turn and I really didn't want a big project.....

 

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You could test the fuel pump output at the carb. YF was supposed to have 2-1/2 to 3psi pressure. You must ALSO check the output volume.

Both are specced in the FSM.

 

Kink in fuel line?
Filter sock on sending unit in tank?
Is u r tank vented?
Unhook fuel line just before pump, blow air through line, hook back up,
If that fixes it, trash on fuel sender sock.

 

I had a fuel pump that was about a year old fail and cause similar problem on my V6.

 

My fuel pump was changed and works well. My main problem was cleaning the carb and the Solex has many parts to clean, not useful to take it away, just clean in unscrewing the parts, there are at least 3 parts + fuel part with 4 screws, spring inside, filter, be careful.
I just can say that my Jeep works perfectly now, winter or summer. Also check the ignition maybe a short circuit somewhere around the plugs, to check easily. Sparks outside!