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

[jakespop]

Hope you figure it out. Fortunately I haven't had the problem come back one time since cutting the magnets in half about 8k miles ago ('13 3.8).

 

[craigt]

I don't know about this fix.... for months I drove around with the magnets reversed in polarity so the door would stay open. I still experienced a little dead pedal although it was improved. A week ago I swapped my K&N drop in filter back in and removed the flapper door completely. Not much change but I still get the dead pedal problem and THIS is when it happens....

When I stop quick and go to take off again. I think this is a transmission problem or programming problem and NOT an engine air intake problem. I don't think our 8 speed transmissions get back to first gear quick enough. If I am driving through a neighborhood, come to a quick stop at a sign and punch the gas pedal there is at least a 2 second delay where the car does NOTHING. The engine doesn't rev, it just sits there thinking about what to do. Eventually the transmission gets to first gear and the car takes off. This isn't such an issue driving around a neighborhood but it can be on the highway when navigating through heavy traffic, quick stop plus heavy acceleration to merge to another lane and the car just sits there annoyingly.

I think the programming on these cars is horrible too. It reminds me of my trailblazer. GM designed the programing so that only 70 or 80 percent of the power would go to the rear wheels when you punched it from a stop. This was of course done only to improve the life of the drivetrain components. I think Hyundai is doing the same thing.

+1

This is exactly what happens more often than not when there is an issue of lack of immediate acceleration.

I "proved" this theory (at least to my satisfaction) by using the manual mode of the transmission. Since first can get above 20, I kept it in 1st at 20mph, slowed quickly, and then stomped on the gas. Immediate acceleration (and a little tire spin to boot). In auto mode, at 20 the auto is in 3rd or 4th. Slowed quickly, and then stomped on the gas. I had time to make a cup of coffee, sip it, read the paper, and take a nap. Then the car took off.

I modified the intake flapper with a few layers of gorilla tape. It helps in some cases, but *not* in the scenario above.

 

[SoCalGen]

+1

This is exactly what happens more often than not when there is an issue of lack of immediate acceleration.

I "proved" this theory (at least to my satisfaction) by using the manual mode of the transmission. Since first can get above 20, I kept it in 1st at 20mph, slowed quickly, and then stomped on the gas. Immediate acceleration (and a little tire spin to boot). In auto mode, at 20 the auto is in 3rd or 4th. Slowed quickly, and then stomped on the gas. I had time to make a cup of coffee, sip it, read the paper, and take a nap. Then the car took off.

I modified the intake flapper with a few layers of gorilla tape. It helps in some cases, but *not* in the scenario above.

Yeah I wish there was a way to change the transmission programming. I wonder if just driving in manual mode all the time would help? Probably a huge fuel economy loss revving the engine out in every gear though and that would be annoying.

 

[daviderle]

Yeah I wish there was a way to change the transmission programming. I wonder if just driving in manual mode all the time would help? Probably a huge fuel economy loss revving the engine out in every gear though and that would be annoying.

Yes there is, the more you drive it in auto the more the transmission will adapt to your driving style, the important thing is also use the manual to shift down when you slow down...

In my case (8sp R-Spec), in auto mode the gears now change to lower gear when I slow down as soon as I go lower than 1750rpm, and would hold on longer to gears without me doing anything...

 

[amartz]

When I stop quick and go to take off again. I think this is a transmission problem or programming problem and NOT an engine air intake problem. I don't think our 8 speed transmissions get back to first gear quick enough. If I am driving through a neighborhood, come to a quick stop at a sign and punch the gas pedal there is at least a 2 second delay where the car does NOTHING. The engine doesn't rev, it just sits there thinking about what to do. Eventually the transmission gets to first gear and the car takes off.

That's a perfect description of how mine *used* to behave, before I put a little gorilla tape in to loosen the magnet's grip on the door. I used to think it was a transmission programming problem, but I now think it was that the transmission didn't do anything until the engine finally came up to speed, after a couple of seconds, as you stated. I continue to be very happy about the prompt response in exactly the scenario you describe.

 

[Youseethefight]

buy the intake from r2c performance. you will never have dead pedal issues.

 

[MIKES3]

buy the intake from r2c performance. you will never have dead pedal issues.

I agree and I'm currently checking to see if they make it for the Sedan. It doesnt exactly say it on the website. Plus I can pick up because I'm local.

 

[Rloyola0426]

They don't have one for the 2015 V6 sedan

 

[dareckibmw]

I got rid of my anti-skid pad, turned both magnets in that little spot with the flapper open and put them back on. Damn! ....now this car can breath better and a little louder!

Why I didn't do that earlier?

 

[daviderle]

I got rid of my anti-skid pad, turned both magnets in that little spot with the flapper open and put them back on. Damn! ....now this car can breath better and a little louder!

Why I didn't do that earlier?

Well done my man...

Sorry I should have updated this thread before!, I did this a while ago on the R-Spec to match the 2009 4.6 magnet strength.

In conclusion going forward the recommended method would be correcting the magnet strength at the source (?assembly defect?) instead of weakening the magnet using other methods...

______________________________

Help support this site so it can continue supporting you!

 

[pinto127]

For those that flipped both magnets over - how did you remove the magnet on the bottom? I easily removed the magnet on the flapper door, but for the life of me I couldn't tell how to get the other one out! I read through this thread and couldn't find a clear answer. Thanks in advance.

This mod is spot on. Might I suggest not flipping the magnets, but rather there are three total magnets (2 bottom, 1top/on flapper) I simply pulled apart the two bottom magnets, wrapped one in electrical tape til it fit back into the housing. On the top I pulled the magnet and its housing. Wrapped the magnet and stuck it back on the flapper wrapped in tape but with out housing. The tape acts as the new housing and its going nowhere.So I still have a connection when closed (albeit like 80% less than before) and instead of having to pull the flapper up with effort (like befor) I can literally flick it up With little or no effort. Furthermore, if I need to revert back to stock set up I simply remove tape and put magnets back.

I noticed a difference right away with the car. Still have not WOT but acceleration from 70-(80-85) was unaffected and smooth.

PROFIT!!! DO IT NOW. TOO EASY TO REVERSE NOT TO TRY!!!

 

[SoCalGen]

I don't know guys..... the more I think about it the more I think this is simply a transmission problem. I know more air to the engine should elicit a quicker acceleration and maybe it does if already in first gear. But the problem in my car is that the dead pedal happens when I stop quick, the transmission hasn't got down to first gear yet and then I hit the gas. Why Hyundai would program the transmission this way is beyond me. You'd think if the computer see's you're on the brakes and almost at zero mph it would be quick shifting the transmission to first as fast as possible. Maybe they're trying to boost MPG?

I think I'm going to put the flapper and stock air filter back in and see if it's all snake oil or not.

 

[Youseethefight]

an intake helped resolve the problem for me.

 

[SoCalGen]

an intake helped resolve the problem for me.

I'm still under the powertrain warranty for about another 70k miles and don't want to do anything that would give Hyundai a reason to not pay for something that fails.

 

[dmitriylm]

I don't know guys..... the more I think about it the more I think this is simply a transmission problem. I know more air to the engine should elicit a quicker acceleration and maybe it does if already in first gear. But the problem in my car is that the dead pedal happens when I stop quick, the transmission hasn't got down to first gear yet and then I hit the gas. Why Hyundai would program the transmission this way is beyond me. You'd think if the computer see's you're on the brakes and almost at zero mph it would be quick shifting the transmission to first as fast as possible. Maybe they're trying to boost MPG?

I think I'm going to put the flapper and stock air filter back in and see if it's all snake oil or not.

I don't think its the transmission. My car rolls forward as soon as I let off the brakes so engaging 1st isn't an issue. I don't know if I ever noticed a dead pedal or engine falling flat sensation as I pulled the flapper as soon as I got the car and now I'm running a cold air intake.

 

[craigt]

I'm with SoCalGen on this one. IMO, the car rolls forward because even in 3rd gear, the engine can move the car.

 

[dmitriylm]

I'm with SoCalGen on this one. IMO, the car rolls forward because even in 3rd gear, the engine can move the car.

I think he's confused as to what's being described in this thread. This cars transmission definitely makes an effort to sit in the highest gear possible under normal driving conditions but pressing the kick down puts the car into the lowest possible gear with decent urgency. I don't experience any feeling of dead pedal in this car with my current mods. Ultimately what I'm saying is that although the transmission programming does noticeably target the tallest possible gear, I don't believe this contributes to the feeling described here by other members.

 

[SoCalGen]

I think he's confused as to what's being described in this thread. This cars transmission definitely makes an effort to sit in the highest gear possible under normal driving conditions but pressing the kick down puts the car into the lowest possible gear with decent urgency. I don't experience any feeling of dead pedal in this car with my current mods. Ultimately what I'm saying is that although the transmission programming does noticeably target the tallest possible gear, I don't believe this contributes to the feeling described here by other members.

I don't think I'm confused at all. I know that if I'm cruising along at 30mph, stop quick and floor it immediately the car does nothing for at least 2 seconds because the transmission has not went back to first gear. With or without the mod my car does this and at least one or two other people in this thread experience the same thing.

From a standing start with the car for sure being in first there might be a little more pep off the line with the flapper mod. But it's negligible at best. I think I may head to the local drag strip for test and tune and see what the differences are mod v.s. no mod.

 

[dmitriylm]

I don't think I'm confused at all. I know that if I'm cruising along at 30mph, stop quick and floor it immediately the car does nothing for at least 2 seconds because the transmission has not went back to first gear. With or without the mod my car does this and at least one or two other people in this thread experience the same thing.

From a standing start with the car for sure being in first there might be a little more pep off the line with the flapper mod. But it's negligible at best. I think I may head to the local drag strip for test and tune and see what the differences are mod v.s. no mod.

What speed are you slowing down to from 30mph prior to going full throttle?

 

[SoCalGen]

What speed are you slowing down to from 30mph prior to going full throttle?

30mph to 0mph or maybe 30mph down to a rolling 1-3mph then flooring it. There's always at least a 2 second delay if I go from 30-0 hard on the brakes. The car acts like it's confused.

I'm sure it would do the same thing if I was going faster though. The computer must be programmed to assume that someone who's stopping quick isn't going to take off fast so it lets the transmission leisurely shift down to first.