throttle issue

I'm hoping somebody can help me with this.

I bought this 2008 GT a couple months ago it has 11000 miles on it so it's in really nice shape.
the previous owner put a lot into it.
I'm not sure if it has a tune or not.
It has a bigger throttle body different plenum and coil packs and air intake.
when I take my foot off the throttle it takes a few seconds or so to idle down it's just not right.
no check engine lights.
that seems to be the only issue I have.
thanks for any help I can get.

Likely a dashpot setting in the tune. Probably needed with the mods the car has. Without having a hand held tuner or knowing who’s tune is in the car it’s not an easy fix.

100% it has a aftermarket tune

The 4.6 3v has this issue from the factory. Some people don’t really notice or care. Along with a slight hesitation upon take off with a the standard trans.

If they happen to have installed the aftermarket parts without tuning it, then I’m sure it’s far worse.

Did you buy it from an individual or a car lot? Either way you need the hand held tuner that is married to the car and the original stock tune.


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I bought it from I would say the second owner He only drove it to car shows.
I bought it to drive it.
I would say that the original owner is the one that put everything on it.

Mr Don 21 said:

I bought it from I would say the second owner He only drove it to car shows.
I bought it to drive it.
I would say that the original owner is the one that put everything on it.

Click to expand...

Ok, so hopefully others will jump in and correct anything that I tell you that’s incorrect.

1. You will need a good up to date hand held tuner.
2. You will need a reputable tuner to make you a tune file to save to that tuner for your specific mods (Save a copy to a flash drive and on your computer).
3. Take your car to a dealership and have them reflash the computer to stock.
4. Plug in the hand held tuner. Save the stock tune to the tuner, then load the custom tune into the cars PCM. Be sure to save the stock tune on your computer and flash drive.
5. Contact the tuner that supplied the custom tune and get him to tweak the way you want it.
6. Drive and enjoy!


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Mach2burnout said:

Ok, so hopefully others will jump in and correct anything that I tell you that’s incorrect.

1. You will need a good up to date hand held tuner.
2. You will need a reputable tuner to make you a tune file to save to that tuner for your specific mods (Save a copy to a flash drive and on your computer).
3. Take your car to a dealership and have them reflash the computer to stock.
4. Plug in the hand held tuner. Save the stock tune to the tuner, then load the custom tune into the cars PCM. Be sure to save the stock tune on your computer and flash drive.
5. Contact the tuner that supplied the custom tune and get him to tweak the way you want it.
6. Drive and enjoy!

Click to expand...

You've nailed it. Pretty much what I said here:

https://www.mustangevolution.com/threads/lost-tuner.347794/#post-4261737134

Definitely has a tune in it. Only way around is to do above.

Dino Dino Bambino said:

You've nailed it. Pretty much what I said here:

https://www.mustangevolution.com/threads/lost-tuner.347794/#post-4261737134

Click to expand...

The one thing neither of us said is; when you do updates to your SCT hand held, you need to be sure you have back up copies of both the stock tune and the custom tune(s) on your computer and/or flash drive. There is the possibility of the tunes getting wiped when updates are done. This will be in the instructions of the SCT device when you purchase.

I like to keep the extra copy on a flash drive because I have many horror stories of crashed computers.


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Thank you
I'll keep you updated on how everything works out.

Mach2burnout said:

The one thing neither of us said is; when you do updates to your SCT hand held, you need to be sure you have back up copies of both the stock tune and the custom tune(s) on your computer and/or flash drive. There is the possibility of the tunes getting wiped when updates are done. This will be in the instructions of the SCT device when you purchase.

I like to keep the extra copy on a flash drive because I have many horror stories of crashed computers.


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Click to expand...

Having experienced what Mach2 references I quit updating my SCT and X-4 software versions due to that very problem. I run two tunes (operational and one for smog when I need to test). No problems at all modifying tunes or with the laptop. As far as I'm concerned I'll run this way (no X-4 computer/software updates) as long as I own the car. My recommendation is just skip/cancel when asked to update software versions.