2015 Mustang GT - Yesterday the throttle started behaving oddly. Acceleration to travel speed is normal. Then, when you ease back on the throttle to maintain speed, she starts struggling, running rough and losing power. Giving her a little more throttle makes no difference. Giving her a LOT more throttle (80-100%) does. This behavior is consistent and repeatable.

While this is happening, I am getting messages after starting indicating the "Hill Hold" feature is not available. Also, once parked, the tail lights remain lit. They remain lit after I have closed the door and walk away.

She was fine yesterday morning. This all started, all at once, yesterday evening. Thoughts?

 

Was gonna say wheel sensors, but then that tail light thing happened. Brake pedal sensors/switches. Or the harness. You got a rat problem 'round them parts?

Just tossin' that up there to see if it sticks. Just inspect all the wires you can, might find it real quick. Repair quick? Depends on how you wanna go about it.

It could be a computer too, those happen.

Weird.

 

OK, we all know about the chip shortage and all the issues that come with it. We know about some folks remaining on unemployment instead of going back to work. We know about crazy prices for used Mustangs and other vehicles.

It's a perfect storm at dealers. I have an appointment for three weeks from now. They are that backed up. It's pretty much that way throughout the area. If anything is transmission-related, they don't have a transmission tech - they quit, Not enough other techs, either. And parts? Some things are way back-ordered. I heard today about someone who had their F150 at the garage for 9 weeks - just waiting on parts.

I know I have options other than dealer service. But I have had little-to-no success finding a shop I have confidence in where I live.

 

sounds like the computer has gone crazy, might be worth a try, to apply the standard cure for crazy computer: reboot it

for these cars (I'm pretty sure), to reboot: disconnect the battery for about half an hour, then hook it back up; while you're at it, make sure the battery connections are clean and tight

this will clear the "adaptive memory" and it will have to learn over again; I am not sure exactly what that means, but I don't think it will hurt anything

if that doesn't help . . . well . . . . at least it was really easy to try

 

I had already tried a disconnect-the-battery reset, but no joy. After waiting for weeks, today is finally appointment day. Hopefully I will soon have a diagnosis about what is going on.

 

Good dang luck to ya! Hope it's just (a re-)programmin'!

 

Ditto!

 

OK, the tallight issue is that brake switch up on the pivot point of the pedal.

The odd engine behavior is one of the intake runners. Looking at a replacement.

 

That's good to hear!

/And yet another unrelated happenstance causes worrisomeness of doom... silly complicated machines...
//Although the intake runner bein' cracked is still worrisome, but... less so, yes? Yes.

 

Agreed, my friend. This is two large expenses this year on a not-yet seven year-old car, though. (Replaced the AC compressor at the beginning of summer,)

If she demands another large cash injection soon, she may need to become someone else's problem. This is too soon in the life of this car to require this sort of work, in my view.

 

And finally, an update. Parts are supposed to arrive November 17th.

 

Another update. Parts now available December 14th.

 

It turns out the service guy has just been pushing four weeks at a time, kicking the can down the road.

I stopped in there yesterday. According to the parts counter, the is no anticipated date for parts. There's 156 other people somewhere like me, waiting for intake runners.

A gent I know had to wait almost 9 months to get his F150 back. (Different issues.) I sure hope my wait doesn't turn into that.
.

 

thanks for the update and sorry to hear about the delays . . . such is life in the age of COVID

 

OK, the intake manifolds are showing up in the system now, with some releasing January 20th and more at the end of the month. This is according to the local parts counter. We shall see.

 

Finally - parts are in. I hope to have her back by the end of the week.

I confirmed it is an IMRC actuator shaft failure in the intake manifold - a problem that goes back to 1996 in the design. Ford is finally releasing an updated manifold.

 

thanks for the update . . . it's a sad story but gladly it sounds like the end is near (hopefully)

 

Finally - she is home.

In the past, I have been pretty happy with the service at my dealer. This time, not so much.

I'm not complaining about the long wait or the actual primary issue, That's on Ford, not them. That, and all the supply chain issues.

But back on October 5th, when I dropped her off, I also specified an oil/filter change. Reminded the service writer when he called me Monday to let me know the manifold was finally in. The oil/filter change was not done. The computer is still nagging for it, and it isn't on the worksheet/receipt. I have a check engine light. After their "multi-point" check, my tires are at 22lbs. all the way around. That's more than a bit disappointing.

She does run great again, at least. But she'll be going back.

 

Everything is all done (before the snow arrived yesterday), and she's back in the barn.

 

And just tell her Soon(tm). Soon(tm) there will be ramming around the twisty roads, yes? Yes.