74 CJ5 Misfire-Backfire Help

Ok new carb and she is back to running like she use to. I still have the old carb and one day I am going to tear it apart and try to figure out where we went wrong on its rebuild, but for now I am going to just drive it.

 

Glad your back on the road again.

 

I was having similar problems after I rebuilt my 2100 with a walker rebuild kit. Turns out the insulator gasket they have in the rebuild kit isn't thick enough causing a vacuum leak. Bought a felpro gasket and now it runs great!

 

BTT for some help.

I haven't been able to drive this thing as much since we got it all sorted out. it still runs great at first, but after 5-10 mins of driving sometimes it randomly wants to sputter/miss. this time there is no backfire and i thought I had it figured out with the timing of happening always after turning but that is not the case. Randomly it will sputter or miss, sometimes after turning at a light or stop sign, but its not consistent. its driveable but I would like the figure this out. It may only do it once every 5-10 mins, or 2x in 3 mins, its just randomn. It will run 100% in the garage and giving it gas, will not miss.Right now we over the summer this is the list of new parts.

New 8mm MSD wires
New GM HEI unit/dizzy
New fuel pump and Filter
new/rebuilt from parts store carb
new plugs.

 

I FOUND IT, I FOUND IT......by accident.

Thursday in the evening i learned the hard way that my headlight switch wouldn't stay on, so after rigging something up on the side of the road we got it home. Friday replaced the switch, and finally the lights worked. the battery was getting old and not holding a charge so we had it running charging the battery while fooling with the wires trying to hook up the switch and low and behold after wiggling these 2 wires by accident it would cut out and miss. fixed it and so far so good. I think this winter I am going to install a new wire harness and tilt column.

 

Hooraah. Those intermittent elect problems can really be a bugger-bear. There has been more than one vehicle scrapped because of it.

 

Keep in mind that low input voltage at your coil can affect your ignition system. I still suspect more of an electrical problem than a fuel problem. Isolate the symptoms from fuel and electrical. The old adage of "it's fuel, fire or sumptin" is 100% correct but that doesn't fix anything. Put a fresh charge on the battery and see if that makes it run better (once had a ford 8n tractor that ran great for a while then when the battery voltage got low due to inadequate charging, it ran like it only had 2 cylinders firing), also check the dist shaft side play, it can cause problems that are not easily seen, no side play is best. If you suspect a fuel problem still, rig up an electric pump and run it out of a bucket or fuel can, (standard safety precautions apply), this will isolate the the fuel system (tank, pump, lines) from the engine side of the fuel system.

 

:iagree: