I changed the fuel filter on my 1992 jeep Comanche. Now truck wont idle, and starts to backfire. Also, just after I changed the filter I put five gallons Of fuel. Not sure if air in fuel line or bad gas. But truck wont run now. The only reason I changed the fuel filer was because the rubber fuel line split.

SOURCE: Help

ive run into this once before and it turned out to be the intake valve spring was broken not giving the correct seat pressure. not sure its your problem but it looks like you have covered all the other bases.

SOURCE: 1992 jeep wrangler with faulty acceleration. It

It is possibly the O2 sensor. I had some issues with early 90's 4.0 liters where the O2 sensor would stick rich under heavy acceleration and would cause it to lean out and bog down. It felt like a rochester four barrel flat spot on an old chevy. I hope this helps.

SOURCE: 89 jeep yj wont keep running

If it's not injected, the idle circuit in the carb either isn't adjusted properly or is plugged, or the float level is too low. A vacuum leak can also do that.

SOURCE: 1987 jeep wrangle will not start or run

Uncouple the fuel line coming from the pump at the carburetor, place a clean can under the line, and have someone operate the starter--you should have fuel shoot from the line in spurts as the engine turns. If it does, then the entry port on the carburetor is plugged. Remove the float assembly and pull out the float needle valve. Hook the fuel line back to the carburetor and try the starter again, there should be fuel pumping into the float bowl. If not, check to see if there is a filter on the fuel inlet path that may be plugged. If no filter, remove the float needle seat to see if something is blocking the fuel passage. If all else fails, use compressed air to blow backwards through the needle seat (remove the fuel line again). Hope some of this helps!

SOURCE: 1987 jeep comanche with4.0 will

have you checked the crank position sensor? when this baby goes the engine will start and run for one or two seconds then die like its out of gas.

Also the ignition switch may be suspect.