TLDR:
I experienced a flashing CEL while accelerating this morning. This happened twice during the initial part (less than 4 miles) of my morning commute. It only occurred as RPMs went over 3,000. The Jeep felt as if starving for fuel but did not choke out. Weather was low 60s and heavy, dense fog.
I understand that the CEL I saw is an alert notifying the driver that the vehicle is pushing raw fuel into the exhaust. It's not a good thing or something to ignore. I’m hoping some more background may help any armchair assessments.
Current Conditions:
The Jeep is an ’05 Unlimited, 6-speed manual and has 108,138 miles. It is not a daily driver, so it gets used intermittently; usually once or twice a week.
I have not recently changed any sensors or major mechanical items. FWIW, I changed oil on 19 Nov 2022 (Castrol High Mileage 10W-30 and Wix filter).
At two recent startups (today and last week) the initial starting RPM seemed ever so slightly higher before it settled into what I would consider “normal” startup RPM range. However, there has been no problems starting or normal idling. Normal (at temperature) idle is routinely lower than at inital startup.
I had traveled about 2 miles from the house when the first flashing CEL occurred as I merged onto another road. I noticed the starved feeling before the light began flashing. The second time occurred just under a mile later at another merge. Again, I noticed the starved feeling before the light triggered.
A quick scan of all gauges each time the CEL flashed showed normal ranges on electrical, oil pressure, and temperature (it may not have even reached full, operational temperature). I turned around at 4 miles into the trip to take it home, but neither the flashing CEL nor the starving feeling occurred again so I turned around and drove to work; 30 total miles.
A few minutes after arriving at work I opened the oil fill and checked internally; I did not see antifreeze in there. (As an aside, it is internally marked “Tupy”. That’s the good one, right?) I also checked for any stored codes and have none.
Maintenance Notes:
Back on 29 Mar 2020, at 102,600 miles I put in AutoLite Iridium XP plugs. At the time I noticed what looked like a crack on the coil rail almost centered between two of the coil packs. However, having never experienced problems with it, I reinstalled and let ride. Those plugs have been good to me up to this point.
In 2021, I replaced the oil pump drive assembly (OPDA) with a Crown unit on 17 Apr (104,915 miles) and then replaced the idle air controller (IAC) with a new Mopar unit on 30 May (105,655 miles). At the time of the IAC swap, I also removed and cleaned the throttle body. Vehicle has been relatively smooth at idle since.
Initial Thoughts:
Despite my inital panic, I’m trying to keep optimistic.
I mention the weather because it reminded me of the days when a crack in a distributor cap or along the plug wires would become very apparent in heavy-wet conditions (like rain or heavy fog) such as I had this morning. I’m entertaining that it may be the coil rail and thinking of starting there. I do not have a spare, so it would just be a “yup, it’s cracked” assessment, but at least I could then inspect the plugs. When looking for plug fouling; is there any specific plug to check, or a good description of what the plugs should NOT look like?
If I do need to replace the coil rail, I understand Mopar is preferred; however, if that is not available, what is the best alternative?
I’ve also been considering (based on reading other pages here) replacing all O2 sensors. The current set looks original, so they are most likely due for replacement. Should I just start there?
I thank the group for any guidance/advice you may offer up.
I experienced a flashing CEL while accelerating this morning. This happened twice during the initial part (less than 4 miles) of my morning commute. It only occurred as RPMs went over 3,000. The Jeep felt as if starving for fuel but did not choke out. Weather was low 60s and heavy, dense fog.
I understand that the CEL I saw is an alert notifying the driver that the vehicle is pushing raw fuel into the exhaust. It's not a good thing or something to ignore. I’m hoping some more background may help any armchair assessments.
Current Conditions:
The Jeep is an ’05 Unlimited, 6-speed manual and has 108,138 miles. It is not a daily driver, so it gets used intermittently; usually once or twice a week.
I have not recently changed any sensors or major mechanical items. FWIW, I changed oil on 19 Nov 2022 (Castrol High Mileage 10W-30 and Wix filter).
At two recent startups (today and last week) the initial starting RPM seemed ever so slightly higher before it settled into what I would consider “normal” startup RPM range. However, there has been no problems starting or normal idling. Normal (at temperature) idle is routinely lower than at inital startup.
I had traveled about 2 miles from the house when the first flashing CEL occurred as I merged onto another road. I noticed the starved feeling before the light began flashing. The second time occurred just under a mile later at another merge. Again, I noticed the starved feeling before the light triggered.
A quick scan of all gauges each time the CEL flashed showed normal ranges on electrical, oil pressure, and temperature (it may not have even reached full, operational temperature). I turned around at 4 miles into the trip to take it home, but neither the flashing CEL nor the starving feeling occurred again so I turned around and drove to work; 30 total miles.
A few minutes after arriving at work I opened the oil fill and checked internally; I did not see antifreeze in there. (As an aside, it is internally marked “Tupy”. That’s the good one, right?) I also checked for any stored codes and have none.
Maintenance Notes:
Back on 29 Mar 2020, at 102,600 miles I put in AutoLite Iridium XP plugs. At the time I noticed what looked like a crack on the coil rail almost centered between two of the coil packs. However, having never experienced problems with it, I reinstalled and let ride. Those plugs have been good to me up to this point.
In 2021, I replaced the oil pump drive assembly (OPDA) with a Crown unit on 17 Apr (104,915 miles) and then replaced the idle air controller (IAC) with a new Mopar unit on 30 May (105,655 miles). At the time of the IAC swap, I also removed and cleaned the throttle body. Vehicle has been relatively smooth at idle since.
Initial Thoughts:
Despite my inital panic, I’m trying to keep optimistic.
I mention the weather because it reminded me of the days when a crack in a distributor cap or along the plug wires would become very apparent in heavy-wet conditions (like rain or heavy fog) such as I had this morning. I’m entertaining that it may be the coil rail and thinking of starting there. I do not have a spare, so it would just be a “yup, it’s cracked” assessment, but at least I could then inspect the plugs. When looking for plug fouling; is there any specific plug to check, or a good description of what the plugs should NOT look like?
If I do need to replace the coil rail, I understand Mopar is preferred; however, if that is not available, what is the best alternative?
I’ve also been considering (based on reading other pages here) replacing all O2 sensors. The current set looks original, so they are most likely due for replacement. Should I just start there?
I thank the group for any guidance/advice you may offer up.
