sketchy620

Ok, so i have a 2003 mustang gt, automatic. I just bought it a few months ago. Already had a cold air intake, cheap throttle body (no plenum), and flowmasters. It seems like since i've had the car it misses out. Thats really the only way to explain it, after it shifts into 3rd, it like revs up and down really fast, and does not stay steady at all...like it wants to shift again or something..idk it's hard to explain. It's not terrible, but when your right around the rpm and speed that it does it, it gets to be rather annoying. Also seems rather sluggish if I go to mildly get on it when it's doing that. I have to really step on it.

I just recently put in 4.10 gears, and it still does it..but it doesn't seem like it's as bad as it was. Maybe its just me..haha..But I'm about to get a sct handheld tuner off of american muscle. Cannot wait for that, I have read nothing but great things about it, and how its really effective on automatics. I'm hoping once I get it tuned that it will clear up the little miss that it's doing. I was waiting to get the tuner to see if it will before i took it to have it tested by a mechanic. Assuming it could be spark plug, fuel filter, vacuum leak etc. who knows.

Anywho, whats your guy's opinions?

1998Slow 'Stang

I don't know a whole lot about auto's, but that sure sounds like your trans is having issues to me.

sketchy620

somebody else mentioned that too. I sure hope not, im really hoping the tuner adjusts it. Not really counting on it though.

1998Slow 'Stang

Sorry to be the bearer of bad new man.

MustangMan00

did you put gears in and not have it tuned or calibrated for them?

if so, your car will act extremely weird on how it shifts and acts because it thinks its going a different speed than it actually is

aerbourne

i thought this thread was going to have a picture of a bikini girl on your hood...

sketchy620

yeah, its not been tuned yet.. However, it was doing this before I put the gears in it. It almost seems like it's not as bad maybe,? since i put the gears in..lol..like I said, maybe it's just me. I'm just really hoping the tuner will do the trick...

AMDanBailer

OP, it's most likely the gear-change and no tune. Automatics tend to freak out a little bit in terms of when to shift, when gears are installed with no tune. The tuner should definitely help.


However, I would definitely check your spark plugs/ignition components before installing the tune, just to be sure you don't need new spark plugs or plug wires.


Good luck!

Let us know how the tuner works out!

supermario

Hey OP, I have the same issues and I know what your talking about. It feels like when you step on it, it shifts but too fast of a shift and doesnt take off as you think it should?

A Ford mechanic told me that also can be the torque converter kicking in (so to speak) and thats normal for automatics to feel that way. Im not sure but its really annoying becus it feels like the engine want to go but tranny doesnt let it.

On a side note, my tranny takes a few seconds before it kicks into reverse and a transmission shop said if it has delay when you put it in reverse, the tranny may be going out soon.

Repzard

After install of parts you list OP.
Did you unplug battery so computer will relearn?
Just shooting up a idea that could cause a issue with bolt ons.