Jeep towed home yesterday (engine)

jeepins

jeepins

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Driving to work bright and early yesterday morning. I'm about 15mi from home going about 70mph down the highway when my engine sputtered a bit. I let off the gas and got over a couple of lanes instinctively. Soon as I gave it the throttle it sputtered and backfired so I immediately got off the freeway and onto a side street and shut it down. No engine light, no strange gauges, all pressures and temps normal. Looked underneath and nothing. Opened hood, only thing I did was depress the schrader valve on the fuel rail and fuel sprayed out. Have 1/2 tank of fuel.

Let it sit for a min or two and tried to start. Turned over just fine but didn't want to start. Let it cool a bit more for about 30 min and started right up. As soon as I pressed the gas pedal it sputtered and died again and had trouble starting again after that. Called a tow and got it towed home.

Jumped in my pickup and went to work. Came home and Jeep started right up. Hooked a code reader to it and nothing. Let it idle for about 5 min, hit the gas a few times and no problems.

This morning I hooked a fuel pressure gauge to it and sat at 46 psi at idle. Shut it off and sat at 45 psi for more than 15 min afterwards. Disconnected pressure gauge, started it up and let it idle up to operating temp, runs fine. Dumped in a bottle of the Techron fuel additive just because I had one in the garage.

Basically I still don't know what caused this. I kept thinking fuel pump but I changed mine out about 5 years ago and fuel pressure gauge sorta ruled that out. Maybe water in the fuel or bad gas? But since last fill up, nothing happened before that, not even a hiccup of any kind. We did have quite a bit of rain past week and I washed it really good night before (hence the shiny pic).

Thoughts on anything else I can check or troubleshoot? i'm afraid of leaving my driveway to be honest without knowing what the stall was from.
 
Simple stuff first. Throttle position sensor? If the TPS is saying the throttle is wide open, that could explain the rich mixture of fuel that cause your backfire.
 
Just a SWAG but it sounds like MAYBE a PCM issue. Once the PCM get hot it stops working and then once it cools back off it will work again. Drivability issues are always hard to track down and figure out.

I was driving down the road one day and my engine cut out on me. I had a 4 cyl 2.5 so a little different than yours. Sitting on the side of the road with the hood up trying to figure out what is wrong. Turned out to be the plug going to the coil on the back of the engine. Plugged it back in all the way and the rig ran fine again.
 
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Also check your ASD relay. Happened to me. Jeep drove fine but it just died. To check after your jeep sits a while swap with one of the relays like the horn (they are the same) fire it up and let it run to see if it kills. Will need to run a while perhaps an hour. If that works just replace your relay.
 
jeepins said:
View attachment 140418

Driving to work bright and early yesterday morning. I'm about 15mi from home going about 70mph down the highway when my engine sputtered a bit. I let off the gas and got over a couple of lanes instinctively. Soon as I gave it the throttle it sputtered and backfired so I immediately got off the freeway and onto a side street and shut it down. No engine light, no strange gauges, all pressures and temps normal. Looked underneath and nothing. Opened hood, only thing I did was depress the schrader valve on the fuel rail and fuel sprayed out. Have 1/2 tank of fuel.

Let it sit for a min or two and tried to start. Turned over just fine but didn't want to start. Let it cool a bit more for about 30 min and started right up. As soon as I pressed the gas pedal it sputtered and died again and had trouble starting again after that. Called a tow and got it towed home.

Jumped in my pickup and went to work. Came home and Jeep started right up. Hooked a code reader to it and nothing. Let it idle for about 5 min, hit the gas a few times and no problems.

This morning I hooked a fuel pressure gauge to it and sat at 46 psi at idle. Shut it off and sat at 45 psi for more than 15 min afterwards. Disconnected pressure gauge, started it up and let it idle up to operating temp, runs fine. Dumped in a bottle of the Techron fuel additive just because I had one in the garage.

Basically I still don't know what caused this. I kept thinking fuel pump but I changed mine out about 5 years ago and fuel pressure gauge sorta ruled that out. Maybe water in the fuel or bad gas? But since last fill up, nothing happened before that, not even a hiccup of any kind. We did have quite a bit of rain past week and I washed it really good night before (hence the shiny pic).

Thoughts on anything else I can check or troubleshoot? i'm afraid of leaving my driveway to be honest without knowing what the stall was from.
Click to expand...
It's air or fuel and my gut says fuel, maybe bad fuel. If it was electrical it shud have thrown a code.
I'd say some sort of intermittent fuel problem the PCM didn't recognize and hope it doesn't come back.
R u sure ur CEL works...
 
Engine sputtering, turning off randomly, backfiring/miss firing, not starting are usually the symptoms of CPS going bad before it quits completely.
 
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Thanks Indy (and all thus far), appreciate the replies. Will dig some more on this. Had a Toyota friend mention CPS as well but fact that it starts up without any problems, no codes, etc. made him iffy on that one. Sure would make me feel better to find something broken.
 
My first thought was CPS. They often times give problems once fully warm and work properly once cooled. I'd pull it and clean real good and try again.
 
jeepins said:
View attachment 140418

Driving to work bright and early yesterday morning. I'm about 15mi from home going about 70mph down the highway when my engine sputtered a bit. I let off the gas and got over a couple of lanes instinctively. Soon as I gave it the throttle it sputtered and backfired so I immediately got off the freeway and onto a side street and shut it down. No engine light, no strange gauges, all pressures and temps normal. Looked underneath and nothing. Opened hood, only thing I did was depress the schrader valve on the fuel rail and fuel sprayed out. Have 1/2 tank of fuel.

Let it sit for a min or two and tried to start. Turned over just fine but didn't want to start. Let it cool a bit more for about 30 min and started right up. As soon as I pressed the gas pedal it sputtered and died again and had trouble starting again after that. Called a tow and got it towed home.

Jumped in my pickup and went to work. Came home and Jeep started right up. Hooked a code reader to it and nothing. Let it idle for about 5 min, hit the gas a few times and no problems.

This morning I hooked a fuel pressure gauge to it and sat at 46 psi at idle. Shut it off and sat at 45 psi for more than 15 min afterwards. Disconnected pressure gauge, started it up and let it idle up to operating temp, runs fine. Dumped in a bottle of the Techron fuel additive just because I had one in the garage.

Basically I still don't know what caused this. I kept thinking fuel pump but I changed mine out about 5 years ago and fuel pressure gauge sorta ruled that out. Maybe water in the fuel or bad gas? But since last fill up, nothing happened before that, not even a hiccup of any kind. We did have quite a bit of rain past week and I washed it really good night before (hence the shiny pic).

Thoughts on anything else I can check or troubleshoot? i'm afraid of leaving my driveway to be honest without knowing what the stall was from.
Click to expand...
Sounds like Timing Chain Jumped, CPS would turn Ck engine light on, Fuel rail always under pressure
 
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