I have a 1999 Jeep wrangler Sahara with the 4.0 in it. It started to misfire on me so I replaced all the ignition coil, plugs, and cables (one broke) but it is still missing. I’m doing my own research but hope you guys can help. If I take it on the road it spits and sputters but if I jump on the gas it gets up and goes, also if I’m barley cruising it drives fine (5 mph). Any help would be great, thinking possible fueling problem?
Misfiring problem
- Thread starter MasonWhited
- Start date
Double check the ignition wiring to insure that no wires are crossed/reversed. As careful as I try to be I got two wires reversed on my 97 TJ which produced the same problem. And it's not impossible that ignition wires could have been misrouted before you swapped the plugs.
I have heard of even when the ignition wires are installed on the proper plugs, but cheaply built wires are installed and routed parallel to each other a inductive field can periodically cause a misfire.
I experienced this problem years ago on a '69 Cougar XR7 with a 351W.
You can perform a test to see if this is the case.
In a dark area outside start the engine and look for sparks coming off the spark plug wires to ground or jumping between the wires.
I would also remove the distributor cap and look on the inside for thin lines in the cap which is referred to as carbon tracking... which will cause ignition spark arcing...
I experienced this problem years ago on a '69 Cougar XR7 with a 351W.
You can perform a test to see if this is the case.
In a dark area outside start the engine and look for sparks coming off the spark plug wires to ground or jumping between the wires.
I would also remove the distributor cap and look on the inside for thin lines in the cap which is referred to as carbon tracking... which will cause ignition spark arcing...