Dead pedal / “Engine falls flat” potential fix..

[amartz]

So what is the translation for non gear heads? Is the original fix proposed no longer recommended? If not, is there an equally simple alternative?

For the record the "dead" pedal effect routinely rears its head on my '14 R-spec.

Whether the under hood air intake functions as a ram-air is apparently settled in another thread, by some nice testing to get actual results (good job)! This does not directly affect the original issue of getting the air-box flapper door to open the secondary air input at low speeds when you first open the throttle. Myself, and several others, have reported a reduction in delay from almost 2 seonds to less than half a second. This seriously transforms the daily driving experience in a better way. The rest of the discussion was more around full throttle behavior of the two air intakes, which was a little bit astray from the original topic.

 

[radiohack]

So what is the translation for non gear heads? Is the original fix proposed no longer recommended? If not, is there an equally simple alternative?

For the record the "dead" pedal effect routinely rears its head on my '14 R-spec.

My experience was that flipping the magnets that hold the flapper closed reduced magnetism and allowed the flapper to open more easily while also allowing it to fully close in order to maintain some pressure at higher speeds (what they guys above are talking about, which I can't tell if it has decided is an important fact or not ).

The flapper being able to open more easily reduced the time the engine takes to "come to life" from a dead stop for me. I say it would be worth a try for you to flip them.

I found it easiest to remove the air filter, then completely remove the flapper (only one screw on the flapper if memory serves and then it pulls straight up) and flip the magnets on each side, then re-install. The magnets have a plastic piece with a tab that hold them in place. You have to pull the plastic piece straight out to get to the magnet.

 

[rhubarb9999]

I don't think my 2010 4.6 has any scoops over the radiator, but I will look.

I do know that reducing the magnet strength by 'propping' the door open a little has dramatically improved throttle response off the line and in everyday driving. Highway acceleration is excellent as well. I notice no difference before or after the mod on the highway. I just finished a 1200 mile trip in the Genny and could not be happier.

 

[daviderle]

Sorry for being absent for the last couple of days due a bad case of the flu, but I am glad that we are back on track and happy to see progress is being made by some people who are continuing to share their experience.

While casting your vote, Please keep in mind the expected acceleration is around 0.5 seconds (maybe slightly faster for the 12-14), so if one feels / measures a reduction to a half a second and no longer experience the engine 'dying', I would propose we call that 'completely' solving the issue, vs down from 2 seconds response time down to one second? just my two cents.

UPDATE: During lunch, I felt well enough to experiment with the 4.6, I was able to to increase the magant strenth to from '30%' to '100%', observed the following (sorry no OBDII data):

- I was able recreate the 'dead pedal' issue with ease (twice with WOT)!

- Significant engine hesitation for any level of spirited acceleration (pressing the throttle beyond half way).

- Gear changes under any type acceleration were all over the map! As an example:
* While in normal operation, Press the accerator half way, goes down say from 5th to 2nd and away I went.
* With '100%' force, half way throttle results in slight RPM rise, trasmition goes down to 3rd momenterly, then changes back 5th!

In summery a very negative 'experience', I am not sure if the ECU would have adapted over time!?

After putting the magnets back to the original configuration, all I can think about if I had this issue from day one, I would have promptly returned the car after the two year lease was up, if not sooner!

 

[amartz]

While casting your vote, Please keep in mind the expected acceleration is around 0.5 seconds (maybe slightly faster for the 12-14), so if one feels / measures a reduction to a half a second and no longer experience the engine 'dying', I would propose we call that 'completely' solving the issue, vs down from 2 seconds response time down to one second?

In summery a very negative 'experance', I am not sure if the ECU would have adapted over time!?

If you are going to define it that way, can I go back and change my vote? And no, the ECU never learned. I just reprogrammed my right foot to momentarily floor it, then let up to what I really wanted. I'm so glad to not have to do that any more! :-D

 

[daviderle]

If you are going to define it that way, can I go back and change my vote?

It does not appear so!

On top of that, I can not change the poll captions after realizing that the browser auto correct feature, did a little number on what was ment to be "CAI"!

Please SAL, or any moderator who has the ability, if you would be kind enough to correct the heading for two of these options to the correct spelling (CAI) it will be greatly appreciated.

 

[craigt]

Re: Secondary air door/A.K.A Flapper door Experiment

...as the old adage goes: ''the proof is in the pudding'...

Love this (and the other) thread on the flapper door. I did the Gorilla tape method and have improved throttle response. You guys deserve lifetime memberships to this forum.

But..

Poor use of that phrase, as the "old" phase is "The proof of the pudding is in the eating!", which means you need to eat the pudding to know what's inside of it. Modern English has hacked it into the "proof is in the pudding".

Educational session is over. Back to the topic.

 

[Ram Air]

Re: Secondary air door/A.K.A Flapper door Experiment

I've chucked mine out and haven't looked back since (actually, it's in a cupboard in the garage). No more playing with magnet strength, tape or stick on padding for me. Anytime you can reduce the negative work placed on the engine during the intake stroke is going to make the whole process more efficient. That magnet and spring are very strong. I can see where the engine is on the cusp of starving for air at that critical threshold, where it wants to open the flapper door but doesn't quite have enough vacuum to do it. Maybe that is the dreaded dead pedal issue!
If anyone can prove to me what purpose it has, beyond suppressing sound, please tell me . Then I will put it back on.

 

[Youseethefight]

Re: Secondary air door/A.K.A Flapper door Experiment

I've chucked mine out and haven't looked back since (actually, it's in a cupboard in the garage). No more playing with magnet strength, tape or stick on padding for me. Anytime you can reduce the negative work placed on the engine during the intake stroke is going to make the whole process more efficient. That magnet and spring are very strong. I can see where the engine is on the cusp of starving for air at that critical threshold, where it wants to open the flapper door but doesn't quite have enough vacuum to do it. Maybe that is the dreaded dead pedal issue!
If anyone can prove to me what purpose it has, beyond suppressing sound, please tell me . Then I will put it back on.

@RAMAIR

Did the sticky pads over the magnets provide any improvement in responsiveness, especially WOT from a stop?

I noticed a delay when I go WOT from a stop. Very annoying.

Have you noticed any disadvantages from removing the whole flapper assembly?

Has your responsiveness greatly improved?

Any advice would be great thanks.




Joe

 

[Ram Air]

Re: Secondary air door/A.K.A Flapper door Experiment

Joe: Quote
"Did the sticky pads over the magnets provide any improvement in responsiveness, especially WOT from a stop?

I noticed a delay when I go WOT from a stop. Very annoying.

Have you noticed any disadvantages from removing the whole flapper assembly?

Has your responsiveness greatly improved?

Any advice would be great thanks."



Reply:

I did not fool around with pads or magnets long enough to evaluate them. Others have reported good results. I have gone directly to full removal. In 3 tanks of gas I have not noticed any decrease in gas mileage or drivability. Jumping on the gas from 8th to 4th still takes a while. But if you are in a lower gear and go to full throttle it accelerates immediately.
If I have time I may do another controlled ( low tech) test to evaluate if there is any improvement or if its all in my head.
I like the improved sound. It compliments the Dynomax VT's. No more Singer Sewing Machine sound!

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[Cosworth]

This "mod" thread should be stickied on the general 09-14 forum!

Also, can someone post pictures of how magnets should be flipped? Before vs After??

Well done!

 

[radiohack]

This "mod" thread should be stickied on the general 09-14 forum!

Also, can someone post pictures of how magnets should be flipped? Before vs After??

Well done!

For me, the magnets looked exactly the same before and after being flipped. There was no marking to differentiate the sides. This is why it's important to pull the magnet out, turn your hand, and put it back in! If you set it down you may never figure out how it was originally

Just to reiterate The magnet is a perfect rectangular block. Don't take your fingers off it.

 

[amartz]

I wonder if a permanent marker would help?

 

[DJR17]

1st off just want to say thanks for all the work on finding a solution to this problem. 1 thing that might not be a bad idea is to change the title of this thread though. For me the term "dead pedal" is the left foot "dead" pedal rest inside of the foot well. Delayed acceleration or something like that maybe.. I'll be flipping some magnets later today and let y'all know.. Thanks again!

 

[daviderle]

Re: Dead accelerator pedal / “Engine falls flat” potential fix..

1st off just want to say thanks for all the work on finding a solution to this problem. 1 thing that might not be a bad idea is to change the title of this thread though. For me the term "dead pedal" is the left foot "dead" pedal rest inside of the foot well. Delayed acceleration or something like that maybe.. I'll be flipping some magnets later today and let y'all know.. Thanks again!

You are most welcome...

The title came from people describing the orginal issue, not sure if I can change the orginal heading, but tried to modify the title going forward.

As a reminder around 0.5 of seconds is best we can get, with little or no hesitation is the desired end result and please vote so we can collectivly keep track of this issue.

 

[Youseethefight]

Re: Secondary air door/A.K.A Flapper door Experiment

I took the time this afternoon to remove the Secondary Air door/ Flapper assembly. Took all of maybe 5 minutes.
I don't understand why this restriction is built on these cars.
the magnet for the flapper door is incredibly strong. I really can't get over how strong the magnet is.
The engine must need a ton of vacuum pressure to open it. This must be what causes delay from a dead stop.
More on that later.

I drove the car around and didn't feel much going on at first. I started to do some light acceleration. Did this a few times.
I believe there is some better throttle response.


Next I wanted to try WOT from a dead stop. Before I removed the flapper door and I would go WOT from a stop the car would delay and then get going. No wheel spin with ETC off it would just surge power all the way through 1st.


Now here we go, I go WOT from a dead stop ETC off and the engine soars to life and the tires instantly start to roast!!!
Finally some action!!

Even with ETC off it still engaged before I could get through 1st gear.

I'll need 245 instead of 235 size tires next.

Before I took out the flapper and went WOT from a stop and had no wheel spin or action from the car I was very disappointed. Now after removing the secondary air door/ flapper I couldn't be happier. Once the tires broke loose I had a huge grin on my face.

I definitely recommend doing this mod. I see no point to put the flapper door back on the car. I still don't understand why Hyundai would build the intake this way.

I hope this helps you guys out. If you do this mod please reply back with your results.

 

[Youseethefight]

I took the time this afternoon to remove the Secondary Air door/ Flapper assembly. Took all of maybe 5 minutes.
I don't understand why this restriction is built on these cars.
the magnet for the flapper door is incredibly strong. I really can't get over how strong the magnet is.
The engine must need a ton of vacuum pressure to open it. This must be what causes delay from a dead stop.
More on that later.

I drove the car around and didn't feel much going on at first. I started to do some light acceleration. Did this a few times.
I believe there is some better throttle response.


Next I wanted to try WOT from a dead stop. Before I removed the flapper door and I would go WOT from a stop the car would delay and then get going. No wheel spin with ETC off it would just surge power all the way through 1st.


Now here we go, I go WOT from a dead stop ETC off and the engine soars to life and the tires instantly start to roast!!!
Finally some action!!

Even with ETC off it still engaged before I could get through 1st gear.

I'll need 245 instead of 235 size tires next.

Before I took out the flapper and went WOT from a stop and had no wheel spin or action from the car I was very disappointed. Now after removing the secondary air door/ flapper I couldn't be happier. Once the tires broke loose I had a huge grin on my face.

I definitely recommend doing this mod. I see no point to put the flapper door back on the car. I still don't understand why Hyundai would build the intake this way.

I hope this helps you guys out. If you do this mod please reply back with your results.

 

[OneFunGenesis]

Re: Secondary air door/A.K.A Flapper door Experiment

I removed mine for about 2 months. Got about 2mpg worse so I re-installed it. I am just not gonna mess around with the car much anymore lol. A team of engineers worked on it and I'm just a lowly, humble man haha

 

[amartz]

Re: Secondary air door/A.K.A Flapper door Experiment

I removed mine for about 2 months. Got about 2mpg worse so I re-installed it.

Really? Try flipping the magnets or some duct tape, and see if you get the best of both worlds.

 

[Youseethefight]

Re: Secondary air door/A.K.A Flapper door Experiment

I've noticed a slight drop in mpg like 1 over the past 2 days. but that is probably just from my heavy right foot.

Will keep an update on the MPG.

@OneFunGenesis

Did you notice improved performance? Did you notice change in performance once reinstalled?