2007 Explorer 4.0 Stalling and Hesitation (In Hot Weather)

[Ulver]

Hello all,

2007 Explorer stalls and hesitates. It's only died/stalled while in idle. Hesitates/bucks sometimes when driving, but does not happen all the time. This happens mainly around the afternoon after getting off of work and driving when it's hotter outside.

Codes - 0402 Excessive EGR flow.

I physically checked the EGR valve and there is no carbon buildup around the pintle.

Post fix answer.
Cause of problem was the wiring for the engine harness. Insulation was brittle and had broken off over time for the wiring, which caused many random codes and shorts.

Thanks!

 

[Fix4Dirt]

is the valve stuck open? gasket good? im leaning torward gasket cause it sounds like a vacuum leak, or it could be stuck open too, cause unmetered air...

 

[Ulver]

I was thinking two things.

Either there is carbon build up around the pintle or the solenoid is getting stuck in "open". Guess I'll have to figure out how to run that kind of test on this EGR valve. The 2007 is electronic, so I'll have to check.

As far as unmetered air, I think I could monitor my fuel trims while it's in idle to see if I go too lean.

I also have to mind the possibility that it's not the EGR that's causing the stalling, and that it's just mere coincidence. If there are any ideas on what I can do, please let me know.

 

[Ulver]

One thing that I want to mention is that this seems to only occur when it's hot outside, above 75 degrees. It runs fine in the morning and at night.. But around noon-late noon that's when the symptoms occur the most.

No codes.

I'm getting "fuel pump" on other forums and whatnot.

 

[Fix4Dirt]

the codes do point to a dying fuel pump. however i do wonder if fuel pup has any effect on egr system, hence the code. or this could be a ckmbination of 2 issues. the hesitating and stalling is a fuel pump symptom.

 

[Ulver]

I found multiple wires at and around the electrical connectors (MAF, EGR, TB, ATS, etc.) where wires had insulation missing to a serious degree where the most common bend points are. I thought I got every single one, but I'm guessing I missed some of them because the Explorer is trying to stall out, but isn't so far. Ran it for 45-60 minutes and there were 2 times where it almost did. I guess that counts as a difference from before the wiring fix where it would stall completely and after? That's at least what's going on so far.

Driving it more today so we will see...

 

[1Bad8511]

I found multiple wires at and around the electrical connectors (MAF, EGR, TB, ATS, etc.) where wires had insulation missing to a serious degree where the most common bend points are. I thought I got every single one, but I'm guessing I missed some of them because the Explorer is trying to stall out, but isn't so far. Ran it for 45-60 minutes and there were 2 times where it almost did. I guess that counts as a difference from before the wiring fix where it would stall completely and after? That's at least what's going on so far.

Driving it more today so we will see...

So I had the same problem. Fixed all the wiring and shot 0135, 0155. Checked the egr valve and replaced it. It ran fine for about 30 min then it started shaking and wanted to stall but didn’t. The codes cleared and it doesn’t give me any on the scan. Fuel mixture looks to be good and no vacuum leaks. I’ll keep on out on your post and if I run across a fix I’ll post it here.

Edit: just one more thing, check the valve cover gaskets. I just realized that if it’s running in hotter temps and the gaskets are faulty it would cause a vacuum leak that is only detected under a load, spraying any type of chem to find it at idle would be useless. Just a heads up.

 

[Ulver]

So I had the same problem. Fixed all the wiring and shot 0135, 0155. Checked the egr valve and replaced it. It ran fine for about 30 min then it started shaking and wanted to stall but didn’t. The codes cleared and it doesn’t give me any on the scan. Fuel mixture looks to be good and no vacuum leaks. I’ll keep on out on your post and if I run across a fix I’ll post it here.

Edit: just one more thing, check the valve cover gaskets. I just realized that if it’s running in hotter temps and the gaskets are faulty it would cause a vacuum leak that is only detected under a load, spraying any type of chem to find it at idle would be useless. Just a heads up.

I'll do a check on the gaskets. The fuel trims looked fine on my vehicle as well- both short and long. I ran a live reading while it was stalling out and the STFT looked okay. Is your A/C running okay? Mine seems to go in and out and I don't know if it's related to the electric.. I'll tackle that next though.

I've decided to order a new engine wiring harness. I did the fixes at my connectors and I'm still getting stalling and coughing at idle. Codes are still there, so I'm guessing that the effected areas are more than just at the connectors.

Once I install the wiring harness I'll post an update in this thread. It'll probably a few weeks or so til it's done.

 

[Ulver]

So, I received the engine wiring harness and started working at it. I got most of the engine area undone, however...

I just realized that part of this engine wiring harness sits in the back, underneath the car where the transmission and engine 02 sensors are.

This is going to be tough. I really don't want to start taking things apart. Any suggestions?

 

[donalds]

Just remove your fender liners harnesses are right there

 

[Ulver]

Just remove your fender liners harnesses are right there

You're talking about the splash guard, correct?

I took a peek back there and didn't see where I couldn't access that portion of the engine wiring harness.

Guess I will have to take the entire guard off to see.

 

[donalds]

The inner fender liner big black plastic tub above the tire #2

 

[Ulver]

The inner fender liner big black plastic tub above the tire #2

View attachment 432329

You seem very confident in your guidance, I'll give it another go and take the fender liner off to see if I can get to the wires. Thank you!

 

[Fix4Dirt]

You seem very confident in your guidance, I'll give it another go and take the fender liner off to see if I can get to the wires. Thank you!

donalds is a great guy! super lnowledgable!

 

[allmyEXes]

Mileage?

 

[donalds]

You seem very confident in your guidance, I'll give it another go and take the fender liner off to see if I can get to the wires. Thank you!

I'm sorry I did not mean to be ****y the wires hang behind the engine on top of the transmission bell housing by removing the inner fenders you can then reach your hand right up there and have access

 

[Ulver]

I'm sorry I did not mean to be ****y the wires hang behind the engine on top of the transmission bell housing by removing the inner fenders you can then reach your hand right up there and have access

Not a problem, didn't take it in any negative way. Thank you for your help, this gives me hope that I'll work this out.

 

[Ulver]

Update:

I've completely installed the new engine wiring harness. I honestly can't believe I did it! The transmission/back of engine was the toughest.. Namely the three smaller connections that go to the top of the transmission that all look alike. The O2 sensors weren't as bad as I thought they would be, considering that the wire has to reach to the other side of the transmission with very little space to maneuver. Thank you again @donalds for your help on removing it.

Question: What is this? (picture attached) Does it attach to anything? It popped out while taking the old wires out and I'm not sure if it latches to anything. It looks like a fluid hose with a stop at the end.

 

[Fix4Dirt]

Update:

I've completely installed the new engine wiring harness. I honestly can't believe I did it! The transmission/back of engine was the toughest.. Namely the three smaller connections that go to the top of the transmission that all look alike. The O2 sensors weren't as bad as I thought they would be, considering that the wire has to reach to the other side of the transmission with very little space to maneuver. Thank you again @donalds for your help on removing it.

Question: What is this? (picture attached) Does it attach to anything? It popped out while taking the old wires out and I'm not sure if it latches to anything. It looks like a fluid hose with a stop at the end.

View attachment 432527 View attachment 432528

congratulations!

 

[Ulver]

After driving it for almost a week now I can say that it’s fixed. No stalling, no hesitation or anything. Thanks for your help everyone!