Hello, thanks ahead of time for the input. Ive got a 2001 xj 4.0 4x4 220,000 miles. Im saying that 1 out of 40 engine cold starts it does this. Jump in turn key on, let pump prime, engage the starter and it turns over slow, like its at the top of a compression stroke. It turns over about 4 times, backfires once through the intake and starts. Then rough idle for about 30 seconds and eventually clears out. It runs fine pretty much all the time other than that. If im cruising highway speeds, i notice a slight jumping/ light misfire when trying to accelerate. Thanks again.