Stalling

suicideking

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Riverside, CA
I have an 06 with the 4.0. About a month ago, I was on a trail going slow, waiting for others to catch up. Fuel gage showing about half a tank, and it stalled out. This happened 4 times, heading up hill in 4 low, higher elevation than normal (if that matters). Each time I was able to start it right back up. I finished this trail and headed home early. Drove home with no issues.

Spoke with @mrblaine and a mechanic about the issue. Both said pretty much the same thing. Drive it around, see if it continues to stall. Don't bring it in if it's not somewhat predictable.

So drove it to work for a week and drove it around town a bit. It never stalled in 2wd. A few times I though it was going to stall (fluttering). Twice when I would put in reverse backing out of a parking spot, then shifting to drive. Then once on the freeway in stop and go traffic.

Went out on a trail run Saturday. It seemed to be running fine. Somewhat similar situation, get near the end of the trail. Waiting in traffic for people to catch up, it started stalling again. This time around 10 times total. Pretty much while idle. A few of the times it wouldn't start up right away. Had to give it a few seconds before turning the key.

Headed off the trail in 4hi. Even with a few stop and go times, no stalling. Drove home with no issues.

One other item worth mentioning. Both times when it started stalling, the fuel gauge was at half a tank. Showing half a tank while still on the trail. Then a 90 minute drive home, still showing half a tank, so that can't be right. I thought of topping it off because I'm thinking it should be at a quarter tank or lower. Though if it's the fuel pump, want to bring it to the mechanic as close to empty as possible.

It goes to a mechanic tomorrow evening. Though he's a general mechanic, not a Jeep specialist. So looking for info on what might be causing this and how much it's going to cost.
 
I have an 06 with the 4.0. About a month ago, I was on a trail going slow, waiting for others to catch up. Fuel gage showing about half a tank, and it stalled out. This happened 4 times, heading up hill in 4 low, higher elevation than normal (if that matters). Each time I was able to start it right back up. I finished this trail and headed home early. Drove home with no issues.

Spoke with @mrblaine and a mechanic about the issue. Both said pretty much the same thing. Drive it around, see if it continues to stall. Don't bring it in if it's not somewhat predictable.

So drove it to work for a week and drove it around town a bit. It never stalled in 2wd. A few times I though it was going to stall (fluttering). Twice when I would put in reverse backing out of a parking spot, then shifting to drive. Then once on the freeway in stop and go traffic.

Went out on a trail run Saturday. It seemed to be running fine. Somewhat similar situation, get near the end of the trail. Waiting in traffic for people to catch up, it started stalling again. This time around 10 times total. Pretty much while idle. A few of the times it wouldn't start up right away. Had to give it a few seconds before turning the key.

Headed off the trail in 4hi. Even with a few stop and go times, no stalling. Drove home with no issues.

One other item worth mentioning. Both times when it started stalling, the fuel gauge was at half a tank. Showing half a tank while still on the trail. Then a 90 minute drive home, still showing half a tank, so that can't be right. I thought of topping it off because I'm thinking it should be at a quarter tank or lower. Though if it's the fuel pump, want to bring it to the mechanic as close to empty as possible.

It goes to a mechanic tomorrow evening. Though he's a general mechanic, not a Jeep specialist. So looking for info on what might be causing this and how much it's going to cost.

The fuel gauge points me to a harness issue. The intermittent stalling on the trail and now more frequently points to a harness issue. That said, we need a basics known good function test. I'd start with a known good fuel pump and swap that in first. New does not mean known good so keep that in mind. Once I had a known good pump in place, then fuel and running and start pulling and inspecting harnesses for chafing, melting, loose connections, loose pins and sockets in connectors, moving, shaking, etc. to rule out or find a harness problem.
 
I guess I'd want to know my fuel pressure. Not only during regular operation but when it stalls.

Since you don't have a Schrader valve on your fuel rail you either need to replace it or get a Glowshift or Racetronix 5/16" QD adapter with an 1/8" port.

I have a fuel pressure gauge mounted directly on mine but want to upgrade it to a Glowshift gauge so I can monitor it while driving.

And I'd clean your IAC.


-Mac
 
The fuel gauge points me to a harness issue. The intermittent stalling on the trail and now more frequently points to a harness issue. That said, we need a basics known good function test. I'd start with a known good fuel pump and swap that in first. New does not mean known good so keep that in mind. Once I had a known good pump in place, then fuel and running and start pulling and inspecting harnesses for chafing, melting, loose connections, loose pins and sockets in connectors, moving, shaking, etc. to rule out or find a harness problem.

The fuel pump is original, so hopefully that is the problem. I'll pass on the other info regarding the harness.
 
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I guess I'd want to know my fuel pressure. Not only during regular operation but when it stalls.

Since you don't have a Schrader valve on your fuel rail you either need to replace it or get a Glowshift or Racetronix 5/16" QD adapter with an 1/8" port.

I have a fuel pressure gauge mounted directly on mine but want to upgrade it to a Glowshift gauge so I can monitor it while driving.

And I'd clean your IAC.


-Mac

Will pass along this info as well. Thanks for the reply!
 
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Was it warm? Like outside air temps and/or underhood air temp. Not necessarily coolant temps, but I'm wondering...if its only happening when you're on the trail and moving slowly, is the fuel boiling in the fuel rail and causing a "hiccup" in the delivery? Goes away once you pick up speed and only happening toward the end of the run because of heat soak.
 
Was it warm? Like outside air temps and/or underhood air temp. Not necessarily coolant temps, but I'm wondering...if its only happening when you're on the trail and moving slowly, is the fuel boiling in the fuel rail and causing a "hiccup" in the delivery? Goes away once you pick up speed and only happening toward the end of the run because of heat soak.

All gauges were pretty much in the center. Colder cloudy day with some wind.
 
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Stalling and gauges dropping out are symptoms of the 05, 06 PCM failing if you still have the OEM PCM. Also hard shifts on the AT.

I was going to add something similar, I don't believe the current issue is PCM - seems like wiring and worthwhile to check the usual suspects. Wire out to the gas tank, wire crossing over the trans, wires between the bell housing and firewall, and at the back of the valve cover (as the common starting point).
 
I agree with the other posters regarding the fuel pump.

Take a look for vacuum leaks as well. Perhaps use a scanner and watch to see if there are major fluctuations in fuel trims or IAC positions for little to no apparent reason.

If you have a minor vacuum leak that intermittently seals, that could be enough to stall the engine, especially if the IAC can’t react quickly enough. Similar to when debris gets caught in the PCV orifice.

Also take a look at your fuel tank vapor recovery system. If that fails, it can send slugs of fuel to the engine which can cause it to sputter or stall, almost always at idle, and most often when returning to idle from a higher state.
 
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Is there a recommended fuel pump MFG?

Spoke with the mechanic, he's taking a look. He did mention that he can't get the fuel pump from Jeep. Said it's better if I buy one and bring it to him because it will have a warranty. Vs. harder to do a warranty replacement if he buys it (I would have to take it to him).

He's not a dedicated Jeep mechanic, so also said I might want to look into what aftermarket fuel pump I want. Might want to get it at a popular auto parts store that would be convenient if I was further away from home and wanted to swap it out, Riley's etc.

He did say that as he received it, there's no fuel pressure. So after confirming it's not just simply out of gas, he's going to check fuel lines and such.