Jeep shuts down at interstate speeds

02SteelBlue

02SteelBlue

TJ Enthusiast
Joined
Jan 29, 2019
Messages
412
Location
New Orleans, La
Jeep shuts down at speeds about 60+ mph, after about a half mile.

Will run all day idling in the garage and at speeds up to 45 or so.

Changed crank and cam sensors with mopar ones, as well as a new battery (needed it anyway).

Mechanic is leaning toward PCM. Does that line of thinking track? I've seen a temperature sending unit mentioned here on occasion, would that fit this issue?

Thanks for any help offered.
 
I had a similar issue where I would start to lose power at highway speed after five or ten minutes. It wouldn't just shut off but definitely wouldn't accelerate. It would start to stumble and slow drastically. If I put it in neutral, I could coast smoother onto the shoulder and turn off the jeep, wait about five minutes, start it back up, and continue on my way till it did it again after about ten more minutes of driving. I too could drive for longer periods at lower speeds, but at highway speeds, it would start to act up and sputter and lose power. For me, it ended up being the fuel pump. I replaced it and haven't had the issue since. Not sure that's what you have going on, but it sounded similar to my issue. It should also be pretty simple for your mechanic to test. Perhaps he already did.
 
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Went through similar evolutions. No pattern, but Jeep would just die, sometimes at low speeds, sometimes at high. Sometimes. instrument cluster gauges would zero, but engine would be running. Sometimes it would start right up and go again. Others not. Started with crank sensor and some valve thing I can't remember. Seemed to do the trick for a while, but it would then sporadically die on the highway.

Replaced PCM and it's all been good.
 
Jerry Bransford said:
Does it suddenly just completely die or does it struggle and sputter first?
Click to expand...
It is sudden, no sputter. Once it cools down, it will run fine again at slower speeds.

Talked to the mechanic yesterday. He took it on the interstate and had a scanner plugged in while driving. When the Jeep died the scanner showed a total loss of fuel pressure, so he's taking the tank down today to inspect the pump and hoses.

Appreciate the input from everyone so far.
 
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Jerry Bransford said:
Does it suddenly just completely die or does it struggle and sputter first?
Click to expand...

Hello jerry, i know this is old but i figured id ask you if you know what might be wrong with my 2005 tj unlimited. Ever since i bought it 5 years ago ive had issues with codes for my 02 sensors. The previous owner had replaced as did i all of the 02 sensors with no success. Other than the engine light and sluggishness (just thought a jeep on 35” tires may not be the peppiest vehicle anyways) it has been pretty reliable all along until this weekend. I was on cruise control at about 110km/hr. It started bucking and i turned off cruise control and tried to give it gas to continue but seemed that as soon as rpms would hit 2,500 rpms it would act like a vaacuum leak and bog out. I checked all hoses and clips while on side of road and all seemed fine. Jeep would idle fine but when i hit throttle it would bog out every time when hitting it. I was out of cellular area so i couldnt look anything up so i just turned it off. I restarted within not even a minute and instantly i tried to rev it up and it up would rev normally. I started back down the highway and didnt have any other issues until later. I hit a speedbump a little too fast and all of the gauges went out and came back on and engine light went off. My buddy said it might be the cluster contacts being dirty but i dont think that would have any effect on the running of the vehicle? Back on the highway it did the same sputter/no revs above 2,000-2,500 rpms until i turned it off and on again. 3x over about a 3 1/2 hr drive. Sorry for the long winded message but i figured as much info i could give the better.
Thanks
 
Ljlife said:
Hello jerry, i know this is old but i figured id ask you if you know what might be wrong with my 2005 tj unlimited. Ever since i bought it 5 years ago ive had issues with codes for my 02 sensors. The previous owner had replaced as did i all of the 02 sensors with no success. Other than the engine light and sluggishness (just thought a jeep on 35” tires may not be the peppiest vehicle anyways) it has been pretty reliable all along until this weekend. I was on cruise control at about 110km/hr. It started bucking and i turned off cruise control and tried to give it gas to continue but seemed that as soon as rpms would hit 2,500 rpms it would act like a vaacuum leak and bog out. I checked all hoses and clips while on side of road and all seemed fine. Jeep would idle fine but when i hit throttle it would bog out every time when hitting it. I was out of cellular area so i couldnt look anything up so i just turned it off. I restarted within not even a minute and instantly i tried to rev it up and it up would rev normally. I started back down the highway and didnt have any other issues until later. I hit a speedbump a little too fast and all of the gauges went out and came back on and engine light went off. My buddy said it might be the cluster contacts being dirty but i dont think that would have any effect on the running of the vehicle? Back on the highway it did the same sputter/no revs above 2,000-2,500 rpms until i turned it off and on again. 3x over about a 3 1/2 hr drive. Sorry for the long winded message but i figured as much info i could give the better.
Thanks
Click to expand...
Jerry Bransford said:
Does it suddenly just completely die or does it struggle and sputter first?
Click to expand...

It struggles and sputters and refuses to rev past around 2,500 rpms. It never actually stalls out and idles seemingly normal. Once i turn it off and back on again it will be fine for a while.
 
Ljlife said:
Hello, we installed the NTK ones actually twice with the same result. I thought maybe the first set had an issue so got another set. Now i have a backup set. I cannot remember the codes but i can scan it tomorrow and confirm what they are.
Click to expand...

So just scanned it and it is giving P
Ljlife said:
Hello, we installed the NTK ones actually twice with the same result. I thought maybe the first set had an issue so got another set. Now i have a backup set. I cannot remember the codes but i can scan it tomorrow and confirm what they are.
Click to expand...

i just scanned it and it is giving P0340 and P0344.
 
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