I've had some issues with misfires. This happened over a period of a couple hundred miles…and a few weeks. This isn't my daily driver.
Initially I had some rough running and CEL…I can't remember the exact codes but it was basically a Crank Sensor code and misfire on one of the cylinders. I swapped out the Crank Sensor and it was fine for a test drive but the next outing the rough running came back. I can't remember that code because I was out on the road but it prompted me to swap out the Cam position sensor in the parking lot of the parts store. It seemed fine again…Then a few miles later it started running rougher than normal. It was still drivable but not normal. At this point the CEL didn't come back on but it would occasionally backfire through the intake and once the CEL flickered but didn't stay on.
That prompted me to get a real scan tool and see what the cam sync looked like. It was off 7 degrees so I adjusted that to spec. It certainly runs better but it still has 'spells' of missing and backfiring through the intake. If I floor it - it might sputter a bit then accelerates strongly as if something cleared up temporarily. No CEL …even a flicker - No hidden codes. Starts right up every time and doesn't ever stall.
At this point, based on my experience I feel like it's a plug fouling…but seems too coincidental with these other issues. The jeep appeared to have a recently new coil bar and plugs when I got it but with a 30k interval it may be getting to be time for new plugs. Is there some test or live data that might help diagnose this? I'm new to "real" scan tools so I don't have the wisdom to use what I have effectively yet. I'll get new plugs coming but am debating if I should go ahead and get a coil-bar coming and what else I could look at to firm up a cause.
Initially I had some rough running and CEL…I can't remember the exact codes but it was basically a Crank Sensor code and misfire on one of the cylinders. I swapped out the Crank Sensor and it was fine for a test drive but the next outing the rough running came back. I can't remember that code because I was out on the road but it prompted me to swap out the Cam position sensor in the parking lot of the parts store. It seemed fine again…Then a few miles later it started running rougher than normal. It was still drivable but not normal. At this point the CEL didn't come back on but it would occasionally backfire through the intake and once the CEL flickered but didn't stay on.
That prompted me to get a real scan tool and see what the cam sync looked like. It was off 7 degrees so I adjusted that to spec. It certainly runs better but it still has 'spells' of missing and backfiring through the intake. If I floor it - it might sputter a bit then accelerates strongly as if something cleared up temporarily. No CEL …even a flicker - No hidden codes. Starts right up every time and doesn't ever stall.
At this point, based on my experience I feel like it's a plug fouling…but seems too coincidental with these other issues. The jeep appeared to have a recently new coil bar and plugs when I got it but with a 30k interval it may be getting to be time for new plugs. Is there some test or live data that might help diagnose this? I'm new to "real" scan tools so I don't have the wisdom to use what I have effectively yet. I'll get new plugs coming but am debating if I should go ahead and get a coil-bar coming and what else I could look at to firm up a cause.
