Why am I cutting out?

While cruising at highway speed uphill (under load), my CJ5 is cutting out a bit. The first time I noticed it was while pulling a trailer up a long hill. It just kind of pops and stutter’s a bit. If I let off on the gas it will stop, but if I try to maintain speed uphill or accelerate, it cuts out. This is only at 55-60 mph, if I slow down it does not. I thought it was possible that my fuel pump was on it’s way out, so I changed it this evening, but that did not help. I have a new poly tank, all new fuel lines, and a new fuel filter.

What else should I check? Or is the old Dauntless telling me something worse? Since my HEI conversion I have had the vacuum advance disconnected. Sparky (and I) rebuilt the 2G this spring. Besides that I don’t know what information may be useful.

I appreciate any suggestions.

 

mine was doing the same thing and had me dumbfounded for a while but i happened to find it one day. did you guys use loctite on the carb-base screws?? mine somehow worked themselves loose and the body was moving pivoting on the base. makes a nice little vacume leak when trying to push the jeep down the road.

 

No, we did not use loctite. I will check that.

 

Does the HEI distributor have a mechanical advance? If not you may not have enough timing. If it does, find a dial back to zero timing light and find out what the timing maxes out at. May either be to much timing or not enough.

 

Definately sounds fuel related. Make sure all the fuel line fittings are tight. This happened on one of our racecars once... The suction line from the fuel cell to the pump loosened up at the cell. Air was making its way into the fuel system and caused a fuel starvation problem at higher rpm. It took us forever to figure it out. Also, when was the last time it got a good tune up? A bad spark plug could do the same thing to you.

 

Might be a good time to check your plugs just to see what's on 'em. Rule out plugs, fuel filter (or other collapse in the lines), air filter, and choke linkage. Those are cheap to troubleshoot. You've got a sweet CJ-5...hope all works out!!
-Alan
P.S. I took some great pics of you & Adam, at dinner, your Jeep, etc... but lost my camera only days later on the way home.

 

Floats might be a little low.

 

plugs or wires?

 

Sounds like I will be underneath a dirty CJ5 this evening to check fuel connections. I will probably change the plugs for fun. Like Sparky said, the wires are new, entire fuel delivery system is new or rebuilt, air filter is new.

I do agree that it is fuel related.... it feels just like one time in my grandpa's VW super beetle on the highway. I ignored the cutting out episode on my way somewhere, then had the fuel pump die on me a few hours from home on the way back.

 

mine did about the same thing a while back. would cut out at higher rpm. replased fuel pump and haven't had the problem since.

 

check the carb gaskets. could have a slight vacuum leak @ low speed, and big leak @ high speed.

 

Check to make sure you have a vented gas cap if your tank doesn't have a vent.

 

I get cut-out in the first 2 minutes when I hit the gas unless I have the choke pulled.

 

Fuel is something definitely to check. But, don't rule out the coil going out under load. Usually they die in 2 ways: 1-quit working all together, 1-start to fail under load.

 

The coil was new with the HEI, cap, etc in July, but I suppose anything is possible. I will try to rule out fuel first.

Me too...

If the amount of gas that spills out when I corner hard is any indication, I would say I have plenty of venting

Will do as part of my fuel system inspection over the next few days

Mine too. Wish it would have been my last

 

another thought, check the orings on the carb needles. might have a bad one.. :?

 

I have done several things and continue to have this problem...

A quick question, if I want to re-install my original distributor to diagnose if the HEI (or some part of it) is to blame, is it a problem to leave the ballast resistor bypassed?