Coming to a complete stop, Auto Stop kicks off engine and truck leaps forward

[Rob R]

I was looking to see if there was a problem like that I have had my truck do this to me twice now but not real bad.. It almost seems like the back pressure from the turbo mixes with some fuel residual and it surges just a bit... could that be the same issue you guys seem to be having or not... Curious??

And has anyone had that happen with a Turbo Blowoff valve..,

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[Doc]

My 2019 Lariat 2WD with approx 5000 miles has developed a really dangerous issue. This has happened now about a half dozen times.

When decelerating quickly and coming to a complete stop, the engine cuts off and the truck leaps forward a couple of feet overpowering the brakes.

Once it happened pulling into a parking space and my girl went up the curb. Fortunately no damage. Then yesterday it happed to me coming off a highway exit and just before the stop sign a driver switched lanes and I needed to brake hard. As soon as the truck came to a full stop the engine kicked off and the truck leaped forward and we almost rear ended the car in front.

This is an absolute safety hazard and I'm really aggravated with this truck. She's afraid to drive it. Quite honestly I have a laundry list of issues with the truck. Time top write a lemon law letter. Ford is getting this in writing before it goes to the dealership. Going to try and shoot a video of what's happening.

Believe it or not. I was at the drags at the Cecil Track in Georgia. Staged in water box with traction control off, locker on and S mode. ( auto stop off ). I did a water burnout and when I was almost to a complete stop, it lunged forward about 5 or 6 feet. So I guess this may be related to what’s happening to yours.
Regards

 

[Mokume]

HI Shred5,

A back story... 1990 Aerostar All Wheel Drive...My program... There was a terrible moan in the vehicle which I determined via my Fast Fourier Transform Analyzer to be 2nd order powertrain bending. With a Engine/Transmission/transfer case, the frequency was in the city driving ranger. So I headed out to Livernois to fab up some braces that would brace the transfer case to the transmission bellhouse/ engine Rear Face of Block. It was dramatic improvement, so to do a peer review to make sure, I handed the prototype off to a fellow who was the supervisor of NVH analysis. He drove the Aerostar and was so impressed he got his boss (also my boss) to come for a drive. Both of them agreed that I had solved the problem and we could refine the cobble job into a production system. The way back from the Dearborn Test Track it started to rain, and the manager didn't want get wet, so my peer, Dick K. pulled the prototype into the Executive Garage of Building1, Truck Operations. This was standard operating procedure for brief stops in bad weather. Boss exits the vehicle and Dick lifts his foot off the brake and the vehicle rockets straight forward into the basement wall, splitting two service employees who ware standing in the garage (they service the big wig's vehicles). The crash was so huge that the prototype was toast. What happened? Dick said he was standing on the brake but the vehicle overrode his foot. Dick was hurt in the crash, with a bum knee from hitting the dash. So the vehicle was towed to the scrap yard and impounded for investigation. i was able to remove my bracing I had fabricated at Livernois but my prototype was now toast... Safety did a thorough investigation and finally determined Dick's 13W feet hit the brake and gas pedal at the same time and the result was the Aerostar went to Wide Open Throttle.

There was a redesign to increase the spacing of the brake pedal to the accelerator pedal and an increase of what we call "lift off" from the gas pedal to the brake pedal.... BTW...the Audi 5000 was under investigation for sudden accelerations at this time so Ford was sensitive to this investigation....

Okay...Driving prototypes is a "glamorous" deal, but not without its dangers..Eh?
no
Best,
Phil Schilke
Ranger Vehicle Engineering
Ford Motor Co. Retired

Wide-open throttle = no manifold vacumn = no power brake assist

 

[P. A. Schilke]

Wide-open throttle = no manifold vacumn = no power brake assist

Hi Mokume,

Not True...There a vacuum reservoir and check valve, so at WOT you still have power brakes. It will deplete after several brake applications but you still have power brakes at first, which was the case with poor Dick K. He was pushing hard on what he thought was the brake pedal but was in fact the gas pedal... His other mistake was his seatbelt was unbluckled. He is one of these people that pulls into the parking lot and unbuckles while still driving...it is low speed correct? My wife used to do the same thing. and I told her what happened to Dick, She was hohum about this, so when I was driving and she did this, I stopped the car until she rebuckled and we then proceeded to the parking space.... Now she keeps buckled up until the engine is switched off....

Best,
Phil Schilke
Ranger Vehicle Engineering
Ford Motor Co. Retired

 

[Cape Cruiser]

Hi Mokume,

Not True...There a vacuum reservoir and check valve, so at WOT you still have power brakes. It will deplete after several brake applications but you still have power brakes at first, which was the case with poor Dick K. He was pushing hard on what he thought was the brake pedal but was in fact the gas pedal... His other mistake was his seatbelt was unbluckled. He is one of these people that pulls into the parking lot and unbuckles while still driving...it is low speed correct? My wife used to do the same thing. and I told her what happened to Dick, She was hohum about this, so when I was driving and she did this, I stopped the car until she rebuckled and we then proceeded to the parking space.... Now she keeps buckled up until the engine is switched off....

Best,
Phil Schilke
Ranger Vehicle Engineering
Ford Motor Co. Retired

Phil,dont these also have a vacuum pump for brakes? To me the brakes seem over boosted = soft pedal

 

[Floyd]

Funny, in road racing it is considered a good thing to do the pedal set-up so that it can be "Heel&Toed" so that the brake and throttle can be operated intentionally with the right foot at the same time. mostly to blip the throttle on downshift.
It is a little different though,when the pedals are too close to the same plane without enough lateral space between them.
https://video.search.yahoo.com/sear...=a7a1876ae305f54921e39ddaf7d7ecb7&action=view

 

[P. A. Schilke]

Phil,dont these also have a vacuum pump for brakes? To me the brakes seem over boosted = soft pedal

HI Bret,

This was in reference to the Aerostar that Dick planted in the the basement wall... As for our boosted Ranger, I believe you are correct that there is a vacuum pump. The old SVO 2.3 trubo Mustang used a venturi in a boost bleed line...a very unusual way to get vacuum...here is a picture of one...

Best.
Phil Schilke
Ranger Vehicle Engineering
Ford Motor Co. Retired

 

[Rich_W]

Thanks for all the thoughtful replies and discussion! Nice to hear I'm not alone and many different theories are being discussed. Turbo Back pressure, torque converter, Autostart/stop are all possibilities. Doc's post especially resonates.

My lemon-law letter is in progress. As I understand the law, when the issue is safety related – the manufacturer has one opportunity to correct the nonconformity once notified via certified mail. The reason I'm going this route is simple. I don't want to mess around with an issue like this. I paid for most of this vehicle in cash. I expect a new vehicle to behave like a new vehicle. This is a very serious issue.

Also, when a lemon-law case is opened, Ford will likely send a Ford specialist/representative out to the dealership to evaluate the vehicle. As I understand manufacturers do not let the dealer make decisions nor take any action until the vehicle is inspected by corporate representative.

Essentially it lights a fire. And as a consumer with a problem like this, that is my right.

I look forward to continued discussion.

 

[IdahoRanger]

dont be surprised if they look at it and blame the driver for misapplication of the pedals.

I hope they find a problem and fix it, thats the best result for everyone.

Now a question about lemon lawed vehicles? what happens to them? Are they fixed/resold?

Sold but usually titled as such.

 

[levimac`]

weird, right foot rotated all the way over to the brake pedal and not touching the gas the engine is supposed to be going to idle then stop start turns off motor but still leaps forward with foot on brake; that is an issue that needs service, that should happen no matter who drives the vehicle. Good luck on getting the problem taken care of. I have noticed the need to step harder on brake when coming to a stop. My Ram brake pedal is touchy and have to be careful not to stomp on it, it also has stop start and if the engine is not warmed up stop start doesn't work and if the heater is on high the stop start won't work either; the Rangers stop start is the same as the Ram 1500 e torque 5.7.
Happy New Year.

 

[shred5]

I was looking to see if there was a problem like that I have had my truck do this to me twice now but not real bad.. It almost seems like the back pressure from the turbo mixes with some fuel residual and it surges just a bit... could that be the same issue you guys seem to be having or not... Curious??

I do not know but I know what it felt like. Maybe I am wrong and that is not what happened. It felt to me like when you hi the gas and brake at the same time. I am going to try and recreate the issue in a parking lot and see if I can. If I am wrong it could be very dangerous. Both times it happened was in hard breaking situations. I also was not driving fast or hard, I should not have been in boost.

 

[Rich_W]

I can understand why the hitting the gas and brake at the same time seems logical. However want to be clear it has absolutely nothing to do with what I'm experiencing.

 

[Zaph]

Better get a multi-camera video showing it, and you'll probably have to have one pointed at your feet to prove you're not an idiot and doing something stupid with the brake and the gas... because that's what they will immediately assume.

I’m embarrassed to admit this, but the same thing happened to me and I went back to the dealership and they couldn’t find anything wrong. As I was leaving it happened again. In a test drive with the mechanic, it happened again. This dumba## was applying the brake and the accelerator at the same time. Eco boost won every time!

That is what is happening OP you are hitting the gas at the same time.
Freaked me out.. Took a bit to figure it out after the second time.

I think a lot of you guys can see why I suggested in post #2 that the OP will want multi-camera evidence with one of the cameras pointed at his feet.

OP says that's not it, and it might not be, but a lot of us aren't going to be convinced. The dealer, under the pressure of the lemon law, is certainly not going to be convinced. The brake is indeed soft and goes down far, and this is a situation that could happen. In fact just the other day I was nosing around the forum for people who have firmed up the brake pedal.

OP: I'd get rolling with your video evidence of the issue. To do this, I'd recommend a couple cheap ignition on dashcam style cameras. Point one forward and one with clear view of your feet. I favor Mobius Actioncam cameras. they are small, cheap, clear and can be configured to turn on and loop when power is applied. I use them on my race bikes. You can say you're absolutely sure your foot is not touching the gas but what you say doesn't matter the least bit. It's going to be on you to prove it. Best of luck and I hope it works out for you - either you discover you were indeed touching the gas or you get the evidence you need.

The Mobius cameras are really nice. Got multi-views of some sweet crashes on file.

 

[Rich_W]

Truck is with dealer. Not worried about any video at this time, thanks.

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