Losing power during acceleration

[Redeemer]

So this just happened while I was heading to the store. Driving along in Sport mode but slowed down; RPM around 2500 and I felt a minor power drop. I didn't pay attention at first because from day 1 this car has always had an almost dead spot under acceleration but only while cold. Something I always thought might be a bad TPS but it always went away after coming to operating temp. Well this had been at temp and driven for 20 mins or so when it happened.

After I ran finished at the store and started heading home it happened again, just as I was accelerating to pass someone I just lost power. No strange noises, and the idle was as smooth as can be. It felt almost like wen the engine cuts power when you hit the rev limiter. There was no CEL but I pulled into an Advance Auto and had them run the scanner on it. No codes. Not even old ones. No indication of any malfunction at all. I managed to drive the 12 miles home and it appears to just get worse. It didn't seem to happen under 2K RPM, but what I notices on the gauge is the A/F mix was all over the place. I also discovered I could give it 1 to 2 seconds of throttle and let off for about a second, then resume and I managed to get home in 3rd gear. Really depressing. It feels similar to what I experienced with a GTI I had with an APR tune that had bad coils. Give it any kind of load at all and it just says no.

In terms of background, the car has just over 78K miles and is my daily driver. A few weeks ago I replaced (Had an angry Greek who was 1 step removed from a gypsy replaced to be precise) my water pump, idler pulley, belt tensioner, and both belts and it has been running great. The only thing unordinary I did was dump a can of Seafoam in the tank with a fillup and had no problems with that. Filled up again 2 days ago with Shell 93 Octane. I find it hard to believe there would be so much buildup that something dislodged and clogged an injector so my first thought is maybe a bad MAF sensor or TPS but I am pretty sure MAF would throw a code. I am gonna pull the intake and see if its nasty in there and maybe take out a spark plug as they are original, to look for fouling.

Any and all suggestions welcome. I really don't need to start throwing money at a new problem right now.

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[Southview]

Check to see if your brake lights are staying on. And, if you find small pieces of broken plastic on the floorboard. If so, https://www.mustang6g.com/forums/threads/brake-light-switch-near-pedal-failure.122100/page-3

 

[Redeemer]

Check to see if your brake lights are staying on. And, if you find small pieces of broken plastic on the floorboard. If so, https://www.mustang6g.com/forums/threads/brake-light-switch-near-pedal-failure.122100/page-3

Interesting that you posted this. Last night I took off the intake and was going to have a look at the throttle body when I started getting eaten alive by flies and such so I decided to call it a night. I locked up the car and chatted with the neighbor about the brand new Jeep he bought and he commented that my tail lights were still on. Nothing I cold do to shut them off.

I searched the webs and found this video:

I had a look on the floor and sure enough the exact same piece of broke plastic described in the video is on my floor. It was too dark and cramped to really get in there so I just disconnected the negative battery cable and closed it up for the night.

I would LOVE it if this were the answer. Will keep you guys posted.

 

[Redeemer]

Check to see if your brake lights are staying on. And, if you find small pieces of broken plastic on the floorboard. If so, https://www.mustang6g.com/forums/threads/brake-light-switch-near-pedal-failure.122100/page-3

This was my problem. I shoved the magnet in there and now it is solved. Thank you!

 

[GT Pony]

Yep, the ECU sees the brakes and throttle being active at the same time and think the car is in a "runaway" situation ... remember the "runaway" Toyota fiasco many years ago.

Due to the big fiasco, manufacturers now program the ECU to cut throttle if both the brakes and throttle are active at the same time. The failed little brake switch pad makes the brake lights stay on all the time, and the ECU thinks the brakes are being applied when they really are not.

Ford should put a TSB out about this, and replace that Mickey Mouse brake switch pad with something that doesn't self disintegrate. This could actually be somewhat of a safety issue.

 

[Redeemer]

Yep, the ECU sees the brakes and throttle being active at the same time and think the car is in a "runaway" situation ... remember the "runaway" Toyota fiasco many years ago.

Due to the big fiasco, manufacturers now program the ECU to cut throttle if both the brakes and throttle are active at the same time. The failed little brake switch pad makes the brake lights stay on all the time, and the ECU thinks the brakes are being applied when they really are not.

Ford should put a TSB out about this, and replace that Mickey Mouse brake switch pad with something that doesn't self disintegrate. This could actually be somewhat of a safety issue.

IMO they should put out a full recall. I almost got into an accident and there could be serious liability.

 

[Southview]

IMO they should put out a full recall. I almost got into an accident and there could be serious liability.

Same here. Mine decided to fail as I was merging into 80mph traffic on rt95 with 6 cars following. Talk about a puckering experience.

 

[GT Pony]

Everyone who's had this happen to them should file a safety problem report with the NHTSA - link below.

https://www.nhtsa.gov/report-a-safety-problem#index

 

[Redeemer]

Everyone who's had this happen to them should file a safety problem report with the NHTSA - link below.

https://www.nhtsa.gov/report-a-safety-problem#index

Is it worth it? Does anyone even look at those reports?

 

[GT Pony]

Is it worth it? Does anyone even look at those reports?

The NHTSA does. If they get enough complaints and their investigation shows there is a concern for safety then they can force Ford to do a safety recall.

 

[Blwnsmoke]

Is it worth it? Does anyone even look at those reports?

Yes they absolutely do. Majority of recalls are because of complaints filed.

 

[DivineStrike]

I also just encountered this….(as in today) looks like the rubber just deteriorates over time. I will be filing the report and also letting the dealer know so maybe there is something they can report on their end.

 

[GT Pony]

Here's another video showing a Toyota brake pedal pad part number that works on the S550 Mustangs. Go to the 5 minute mark.

 

[mookieit]

This was my problem. I shoved the magnet in there and now it is solved. Thank you!
[/QU

 

[mookieit]

Had the same problem a few days ago. When I first heard about this, I thought it was silly.

It turned out to be a life saver.

Magnets work like a charm.

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