my xj jeep when cold will skip and jump when the foot is on the acclerator.?

Justin, since I don't know what year your jeep is, it's difficult to answer this completely. But from my experience it could be an ignition problem or fuel problem. If fuel, you need to check the fuel filter for it being clogged. Contaminants are in your fuel, even new fuel you pump into your gas tank. These contaminants are filtered out by the fuel filter. If the fuel filter gets too clogged, it can cause stalling and sometimes no starts, if clogged really bad.

If you have had alot of bad fuel in the past, your gas tank might have alot of contaminants in the tank itself. This will cause problems with the rest of the fuel system. To fix this problem, you have to remove the fuel tank, and have it vated (cleaned out by boiling) This can also, depending on the year of the Jeep, kill a fuel pump, electrical or mechanical fuel pump.

The other situation, is ignition. Like the previous post, it could be your "dizzy", in this case your rotor in your distributor cap. If you trace back any spark plug wire, it will lead to a plastic cap, which all the other wires are connected to. You have to remove this cap to see the rotor. If you need to replace the rotor due to corrosion or wear, I'd suggest you replace the cap also. If you don't have a cap and rotor, you have an ignitioin module or coil pack. These also can go bad. I'd suggest if you want these tested if you have one or the other, to take it to a professional for testing. These emit alot of electricity and can cause a large electrical shock that can be life threatening if you are not careful.

Other possibilities with ignition that can cause this, are the spark plug wires, and spark plugs themselves. If a spark plug wire is bad, it can crack and arch against the block of the motor or another item. This will cause a jerk and sometimes a stalling. Replace the wires. If a plug(s) are bad, this will cause the same feeling, replace them, if you haven't done so in awhile. I recommend replacement for better fuel economy also, but you won't know what condition they are in till you remove a few of them to look at. This is what is called a minor tune-up.

Another thought, you have a catalytic converter on the Jeep. If you have been doing alot of off roading, including water crossings, you could have damaged the converter. Inside this converter is a honeycomb ceramic shell. This unit is basically used for pollutant emissions that your Jeep emits when running. If water gets into this while hot, it can cause the ceramic to crack and break into smaller pieces which will cause lack of power and stalling to the vehicle due to the blockage. You will need to take it to an exhaust or mechanic shop to have it replaced. Best way to check this is have someone rev the gas up and down and another person hold a rag at the exhaust pipe in the rear to see if it pushes the rag out of the way, if it doesn't then it's clogged. Your muffler is another factor, like the converter that can do this. I suggest do not use your hand, you can get burned if the Jeep is warmed up.

Sorry if I can't hit your problem exactly, but if you take this to a mechanic shop and state what type of problem you are having, they have to start with the same issues and troubleshoot this problem the same way.

I have an ol Holden, I had similar probs, I took it to a mechanic3-4 times, He put it on the dyno and all sorts. It would run ok and then ****. Took it to two others. Same thing. Then I was mucking about and it turned out to be the dizzy, It wasnt screwed in tight and was ' spinning in the block' back and forth. If u have the points system, check out your dizzy. If the power aint getting through consistently that could be your problem. I argued with all the mech's and thats why I the prob lasted so long till I sorted it for myself. U can but try!

I stay to inform the tale an island interior the Mediterranean, a hearth is our significant source of warm temperature and we do no longer might want to gentle all of it day or well-known, the temp doesn't bypass lower than 0... i'm continually barefoot and prefer it!!

mine did that to. i gave it a tune up and it stopped.