- City
- Dexter
- State
- MI
Wrote this out to send to a couple friends and thought that it might be worth posting here because it's something 4.0 specific I think that would apply for a swapped CJ.
Kid’s 2001 XJ – NSS recently cleaned/rebuilt. Only issue is slight oil leak at the back of the valve cover. New Mishimoto radiator installed within a thousand miles or so. FlowKooler water pump only has a few thousand miles on it. Runs great, temp rock solid and normal. All incidents here were with full or near full fuel. No CEL during ANY of this.
Couple times where the engine cut off at low speed/idle/shifting situations during the span of a few days while we were at the sand dunes (stopping to back into the parking spot at our dune place it cut off twice and once waiting in traffic to exit the dunes after sunset, in 4H creeping up the exit hill in sand.) Jeep would restart immediately or shortly thereafter. Drove 3 hours on the highway back from the dunes without issue and then around home for a week or so without issue. Jeep never threw any codes. Thought maybe it was a bad tank of gas.
JeepCables kit and new battery installed after the incidents above, during the incident-free period. All connection points cleaned and confirmed tight after install with star/lockwashers better than the stock setup prior.
Friday the Jeep started hesitating driving on the highway (fully “hot” after ~15 min of driving at speed) and died entirely when exiting the highway at the traffic light on the off ramp. Restarted once or twice (not certain, kid wasn’t clear) but then wouldn’t restart. I went to get her, took about 20 minutes to get to her, and by then it started and drove to a nearby gas station lot. Shut it off, checked all battery connections and fuses, all good. Still no CEL. I started and stopped it a couple times there in the lot and it did as expected, no other issues. Decided to swap Jeeps with her and drive the XJ home, about 30 min on backroads. Started and drove it through the nearby industrial park near idle to get to the next street over and it died twice as I did so. Shifted to N and restarted immediately both times. Driving down the road the RPMs would drop to 0 quickly but the engine didn’t stop. Road turned to dirt and I had to go through a couple stop signs and did fine, maybe the third stop sign it cut off and wouldn’t immediately restart. I pushed it back from the intersection slightly to be out of the way, got in, and it started back up. Drove it home the rest of the way, maybe 15 minutes and all it did was a couple RPM drops with a noticeable hesitation/cut off, but it came back immediately after. All with no CELs.
I have since swapped the fuel pump relay and ASD relays out, I again checked all power connections and fuses. I also let it idle in the garage while grabbing/wiggling all of the various wire bundles in the engine bay and tapping/moving every connector I could find, looking for bad wires/connectors and found nothing.
With the two new relays, I have not had another issue in a couple different drives, all of which got it fully hot.
My initial thought was the fuel pump/FP relay but then I thought that if that was cutting out with the engine/computer still on/running that it should have misfired and set a code of some sort. The way this happens, it’s as if the entire engine bay goes dead, ECU, ignition, fuel pump, everything.
That’s when I went to the ASD relay. When I pulled it, two prongs had slight discoloration maybe like they’d gotten hot?
I traded Jeeps with the kid and will drive it back and forth to work and around this week, but this is one of those intermittent electrical issues that drives me nuts.
Open to any thoughts...
Kid’s 2001 XJ – NSS recently cleaned/rebuilt. Only issue is slight oil leak at the back of the valve cover. New Mishimoto radiator installed within a thousand miles or so. FlowKooler water pump only has a few thousand miles on it. Runs great, temp rock solid and normal. All incidents here were with full or near full fuel. No CEL during ANY of this.
Couple times where the engine cut off at low speed/idle/shifting situations during the span of a few days while we were at the sand dunes (stopping to back into the parking spot at our dune place it cut off twice and once waiting in traffic to exit the dunes after sunset, in 4H creeping up the exit hill in sand.) Jeep would restart immediately or shortly thereafter. Drove 3 hours on the highway back from the dunes without issue and then around home for a week or so without issue. Jeep never threw any codes. Thought maybe it was a bad tank of gas.
JeepCables kit and new battery installed after the incidents above, during the incident-free period. All connection points cleaned and confirmed tight after install with star/lockwashers better than the stock setup prior.
Friday the Jeep started hesitating driving on the highway (fully “hot” after ~15 min of driving at speed) and died entirely when exiting the highway at the traffic light on the off ramp. Restarted once or twice (not certain, kid wasn’t clear) but then wouldn’t restart. I went to get her, took about 20 minutes to get to her, and by then it started and drove to a nearby gas station lot. Shut it off, checked all battery connections and fuses, all good. Still no CEL. I started and stopped it a couple times there in the lot and it did as expected, no other issues. Decided to swap Jeeps with her and drive the XJ home, about 30 min on backroads. Started and drove it through the nearby industrial park near idle to get to the next street over and it died twice as I did so. Shifted to N and restarted immediately both times. Driving down the road the RPMs would drop to 0 quickly but the engine didn’t stop. Road turned to dirt and I had to go through a couple stop signs and did fine, maybe the third stop sign it cut off and wouldn’t immediately restart. I pushed it back from the intersection slightly to be out of the way, got in, and it started back up. Drove it home the rest of the way, maybe 15 minutes and all it did was a couple RPM drops with a noticeable hesitation/cut off, but it came back immediately after. All with no CELs.
I have since swapped the fuel pump relay and ASD relays out, I again checked all power connections and fuses. I also let it idle in the garage while grabbing/wiggling all of the various wire bundles in the engine bay and tapping/moving every connector I could find, looking for bad wires/connectors and found nothing.
With the two new relays, I have not had another issue in a couple different drives, all of which got it fully hot.
My initial thought was the fuel pump/FP relay but then I thought that if that was cutting out with the engine/computer still on/running that it should have misfired and set a code of some sort. The way this happens, it’s as if the entire engine bay goes dead, ECU, ignition, fuel pump, everything.
That’s when I went to the ASD relay. When I pulled it, two prongs had slight discoloration maybe like they’d gotten hot?
I traded Jeeps with the kid and will drive it back and forth to work and around this week, but this is one of those intermittent electrical issues that drives me nuts.
Open to any thoughts...
