xj problem

[MudSlinger]

my 92 xj some times when it runs it starts to backfire and buck does anyone know what it is? Help please

[SteveTheFolkie]

Could be one of a number of things - here's what I'd check - in no particular order -

1) ignition timing - make sure it's within spec
2) condition of spark plug wires - if they're cracked and worn you could be grounding to the block rather than the plugs -
3) spark plugs themselves - check the gap
4) change the fuel filter - if you can't recall the last time it was replaced - maybe it's time

[MudSlinger]

would that make it backfire out my snorkel?

[Rick_Bear]

There's something you don't hear about every day. A "cold" in the snorkle.

[MudSlinger]

thats right

[Jeeperjoey]

definitaly sounds like timing problem . But could be cap, rotor, wires , or plugs. Take your pick.

[MudSlinger]

but it seems weird b/c then it clears up and goes away

[Jeeperjoey]

If comes and goes I would maybe look at the distributor. Or maybe a plug wire insulation is bad and its jumping some times.

[Joe Giglio]

My YJ had a similar problem last year. (This next statement might surprise people that know me.) Mine was backfiring and blowing my muffler off. It ran fine or at least OK once it warmed up. It turned out to be a stretched timing chain. The timing was off, but the CPU was able to compensate once it was warm. Replace the O2 sensor along with the timing chain since you likely saturated it with liquid gas.

Joe

[REBELjeeper]

If it does it when your on the throttle, it could very well be a fuel problem.  My YJ has the same problem, but it's not frequent enough yet to worry about it.  It seems to me to be a fuel pump issue. (In tank bugger)  Cause it's intermittent, and fuel pressure drops when it does it, that'd be my educated analysys on mine.  If yous does this to, that'd be a samfe bet.  Mine backfires and all cause it suddenly runsd lean, than rich to compensate once the pump starts working right again.

[MudSlinger]

i put new wires plugs cap and rotor on it and it don't do it much any more and it does it when i run it then shut it off and come out when it still warm

[MudSlinger]

still not fixed going to try a crank sensor to c if it will work or not

[Jeeperjoey]

usually crank sensor goes bad it doesnt run at all.  Make sure none af you plug wires are close to each other and are not hitting gound either. Just a thought

[MudSlinger]

none are touching and hasn't done it since put crank sensor on but we'll see i guess

[MudSlinger]

my xj is still doing it and it sounds like it is getting air locked does anyone know what i should be looking at for this?