Too-Strong 'Throttle' Return Spring ?

richie9mt

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2006 4.0L V6 w/auto. Stock, no mods, 88K miles. Since I've owned it (last November), the throttle spring (for lack of a better term) has been way too strong. There's no giving the pedal a gentle nudge; it's a violent acceleration from a stop. I also own a 2008 Escape I4 and that has a much more gentle throttle tip-in.

If this were a carburetor car I would have no problem; I'd replace the spring with a weaker one. But this is a throttle body, not a link. So, can I just take the jumble of cables off (cruise control too), somehow extract the throttle body, and replace the spring??? I can't find it on the schematic so I don't know if it surrounds the throttle body shaft or is a simple pull-spring.

Anybody replaced theirs??? Might an Escape TB spring fit right on???

I am in deathly fear of letting my sweet, beautiful young lady friend even move the Mustang. I love her and would like that to continue.

Thank you for your time!
 

roddy

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There is no mechanical link between your right foot and the throttle body...it's 'drive by wire'. If it is a spring issue, that spring will be at the gas pedal. It is more likely a throttle position sensor, or throttle body control motor issue. IIRC (it's been a while), an issue with the throttle body will give you the 'wrench' light in the instrument cluster...
 

Flusher

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Does it have a tune?

I had the same issue, with my '05, making it a bit unnerving while pulling away from a stop, with a cop in the lane next to me.

I don't think that the throttle body is the issue. I had the thermostat housing fail, pressure washing the throttle body with coolant, causing the wrench of death dash light. Replacing the throttle body with a new Ford unit made zero change. I had to have the stock tune reinstalled for smog, and that killed the zippyness.

We're not exactly talking about a nitro-injected blown fuel altered here. I'm sure your "sweet, beautiful young lady friend" will learn to handle it. My wife did, even DWA. She actually learned how to drive in that car. You'll learn patience too, I did.

Putting in the stock tune really took the fun out of that car and turned it into a slow POS, not that it was a rocket ship to begin with.
 

richie9mt

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No, no tune that I know of. Haven't cleaned the TB, didn't think it needed it (I was still thinking spring). Haven't looked in the footwell yet, will tomorrow, weather permitting. No dash light; no seepage around thermostat housing.

I've had a prior young lady take offense at my trying to teach her manual shift. A friend, Richard Day, was scheduled to paint that car. I had his name on my kitchen calendar. She wanted to know just why I had "Dick Day" on my schedule. Took a lot of tap dancing and a trip to the local bar to introduce her before she would acknowledge that I was innocent. Stupid, yes; but innocent.

This V6 does not seem slow to me; I also have an '86 Vette with TPI and this car is comparable off a stop.

I suppose I can live with the touchy throttle. Trying to decide if it's worth Ziebarting it now.
 

Flusher

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I had two different dealerships tell me that it didn't have a tune, but logic, and the presence of a JLT intake, indicated otherwise. The smog referee settled that debate.

Tuning a car is a lot easier than tuning a GF or wife, especially if you have an exotic.

Re: the '86 Vette, stock, they are about the same power to weight ratio.
 

richie9mt

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OK, I was able to get a pic of my pedal and a pic of the cheap plastic it's made of (first pic). I could only find one YouTube vid of the pedal disassembled (second pic) Third pic is of the attenuator inside the pedal. There might be a spring behind it but I can't find any pics or references to a pedal spring. Fourth pic is a screen grab of the Shop Service manual description of the Throttle body mentioning springs in the TB.

As mentioned in a post above this, there is no shaft or link or any external connection except an electrical pigtail.

I've pushed my pedal down with engine/key off and there is definitely a spring somewhere; it does feel like it's in the pedal. If it's a simple coil around the pivot I can probably make a spring for it.

The video poster pointed out that the attenuator contacts need to be cleaned off occasionally, he suggested a pencil eraser. My printer cartridge supplier suggests this also.

I'm tempted to get a used pedal off Ebay and detail strip it just to find out if it does indeed have its own return spring...

pedal.jpg

attenuator-contacts_2.jpg

attenuator-contacts.jpg

etb-descript_2.jpg
 

richie9mt

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Found a video on the ETB, took a couple screen grabs of the 'flat' return spring and the 'plunger' or maybe limit/idle adjuster. Doesn't show how to get the split gear off/on or how to adjust it afterwonds.

ETB-spring_3a.jpg ETB-stop_2a.jpg
 

Mailman

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I can't believe none of the 'experts' here have helped you. You're problem isn't a spring or cable or anything mechanical. Your accelerator is actuated by a 'drive by wire' system that doesn't have a wire. What you need is one of the 'throttle enhancement' devices or a tune. I went with a Bama/SCT tune from American Muscle (~$400) and their customer support was perfect. I'm currently running my '05 4.0 5sp. on a 93 octane race tune and it runs amazingly well for being 2 cylinders shy of any kind of respect on this forum. When I first set up the tuner on my car on an 87 octane performance tune the throttle lag (that's what your problem is called) was eliminated.
If you want to see what I went through on the forum, check out my post "Tuners?" Good luck..................the Mailman
 

richie9mt

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If you want to see what I went through on the forum, check out my post "Tuners?"

Interesting reading on several counts. :) So far, the 'lag' or initial resistance is one of only two driving issues I have; the other is the 5-speed automatic shifting too soon in the lower ranges (around town driving is pretty much all I do).

Do the tuners address the shift issue as well???
 

Mailman

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Mine's a stick, but everything I hear about a tune with an automatic is good stuff. The tune can modify your shift points to the way you drive....if that makes sense (?). It wouldn't hurt to get off this forum and talk to some of the after-market companies that fix these problems. And don't let the experts here tell you that American Muscle is a waste of time.
 

Flusher

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I can't believe none of the 'experts' here have helped you. You're problem isn't a spring or cable or anything mechanical. Your accelerator is actuated by a 'drive by wire' system that doesn't have a wire. What you need is one of the 'throttle enhancement' devices or a tune. I went with a Bama/SCT tune from American Muscle (~$400) and their customer support was perfect. I'm currently running my '05 4.0 5sp. on a 93 octane race tune and it runs amazingly well for being 2 cylinders shy of any kind of respect on this forum. When I first set up the tuner on my car on an 87 octane performance tune the throttle lag (that's what your problem is called) was eliminated.
If you want to see what I went through on the forum, check out my post "Tuners?" Good luck..................the Mailman
Interesting reading on several counts. :) So far, the 'lag' or initial resistance is one of only two driving issues I have; the other is the 5-speed automatic shifting too soon in the lower ranges (around town driving is pretty much all I do).

Do the tuners address the shift issue as well???

Maybe I need to go back and take some reading comprehension classes, but I interpreted the issue as TOO MUCH throttle response and that to 210 horsepower V6 is TOO MUCH horsepower for his "sweet, beautiful young lady friend" to handle.

I don't mean any disrespect when I say this, especially after you posted #8 and #9. Whatever spring, you think is the problem, has absolutely nothing to do with your problem. You are not tuning vacuum secondaries on a carburetor. As Mailman posted, there is no mechanical connection between the pedal and the throttle body.

Taking the pedal apart and modifying it is going to substantially increase the risk of the throttle sticking WFO at the most inopportune moment.

Again, it's my impression that the car has too much power. I have to believe that the car ALREADY has a tune. If this is the case, putting in the factory tune is going to make the slower and not twitchy at all. I think you'll hate that. Once the stock tune was reloaded, I really had to stomp the crap out of the throttle to get the car to move

If I am wrong, in my interpretation of the initial question, and the OP is worried, that it will simply take just too long to move the car around the driveway and garage, I agree, adding a tune is a good idea. I wish I wasn't forced to remove my tune. You want to get there while you're still young. A tune will help with that.

Please don't mess with the spring.
 

richie9mt

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Maybe I need to go back and take some reading comprehension classes, but I interpreted the issue as TOO MUCH throttle response...

It's not the throttle response itself; it's the initial effort to get the car in motion. It feels like it takes 10 pounds of pressure to get a throttle response. And then it goes too far and gives you too much response.
 

Flusher

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It's not the throttle response itself; it's the initial effort to get the car in motion. It feels like it takes 10 pounds of pressure to get a throttle response. And then it goes too far and gives you too much response.

To make sure I'm understanding correctly, you depress the accelerator, say 10-degreed (an arbitrary number), and no change in RPM? Like the first 10-degrees (same arbitrary number) is a dead spot? Then, all of a sudden, the RPM jumps to the point where it should be at that 10-degrees?


It sounds like either the pedal/throttle body are out of sync or the pedal is bad.

I would start by scanning it to check for codes. There could be codes that do not result in a Check Engine Light.

Next, use the scanner to perform a throttle body calibration/relearn, not just the disconnecting the battery shown in the YouTube videos. This procedure should walk you through depressing the throttle pedal so that the range of the rotary sensor is tested/learned. The scanner will perform the same procedure for the throttle body.

Start with the cheapest/easiest things first. Don't just throw money at it.
 

RED09GT

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That was confusing up until the last 2 posts.

If what Flusher suggests doesn't work, replace the pedal assembly as a unit and call it a day.
 

richie9mt

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OK, took car out, warmed it up. Idles at 700rpm. Drove down to local FD parking lot [level area]. Dead stop, no brake/no throttle, it creeps along at 700rpm/4mph. Repeatable.

Brought it home to driveway. I only have an Actron CP9575 code reader/blanker, but there were no codes shown.

Took a 3' wooden dowel & flashlight, let car idle @ 700rpm in Park, pressed pedal down with dowel and observed with flashlight. Pedal travels ~1/4" without any change in rpm. Repeatable. Any further, rpm jumps up.

Went back to FD parking lot, real world test. same results. Creeps along @ 700 rom/4mph; depress pedal ~1/4", no change. Repeatable.

To make sure I'm understanding correctly, you depress the accelerator, say 10-degreed (an arbitrary number), and no change in RPM? Like the first 10-degrees (same arbitrary number) is a dead spot? Then, all of a sudden, the RPM jumps to the point where it should be at that 10-degrees?

It sounds like either the pedal/throttle body are out of sync or the pedal is bad.

I would start by scanning it to check for codes. There could be codes that do not result in a Check Engine Light.

Yep, that's what it does. :(

I have the shop manual, I'll check to see if it shows the TB Cal/Relearn. I've been looking at The Forscan site; might be worth a try...
 

richie9mt

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OK, took the TB off, back was sludgey, cleaned it off with TB cleaner. Also cleaned the MAF sensor w/MAF sensor cleaner. Installed new air filter. Took pedal out, cleaned those contacts. Put everything back together and got limp-home mode. :(

Three DTCs are about TB sensor, one is about pedal. It ran really good before I decided to fix it.

While I'm waiting for a new TB sensor (mine has the old round sensor; new square one coming), here's a pic of the pedal spring(s). There's actually two, one inside the other, and they're really strong.

Trying to find the TSB that describes the relearn procedure; tried a dozen of them from this forum and none worked. I'm hoping the sensor fixes all my problems and I can drive it again.

return-springs.jpg
 

richie9mt

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After a TB sensor replacement and ForScan deletion of DTCs, the car once again is running with no problems. I've put 114 miles and a couple dozen starts on it with no recurrence of codes.

I can't decide if the flat spot in the pedal is still there or not. At any rate, It's not as noticeable.

Thanks to all who answered! "Roddy" nailed it. ;)
 

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