what's going on here? when shifting from 1st to 2nd to 3rd, at times the engine revs up atfer engaging the clutch. becoming quite anoying...and embarrassing!

 

how much does it rev...some increase seems to be pretty normal

 

LOL....Welcome to the world of emissions. That's built in to burn off excess fuel between shifts. PITA if you ask me. Get a CAI and a tune and it will be gone.

 

Yeah it's annoying, but we all suffer through it--until a tuner comes along thatis.

 

I've have a tune and mine still does it occasionally. I used to think I wasn't lifting my foot off the throttle enough.

 

Intake and tune hasn't cured my problem.

 

The tune helped a lot but didn't cure it completely. Although I do have days when I shift like a moron, so that could be part of it.

 

I know what you mean when I first drove the mustang first thing I noticed is the way the rev spikes up a little when you push in the clutch and is slow coming down. I asked other friends of mine that have earlier year mustangs and they said its normal theirs did it also. I had a turbo car before the mustang so I got used to a fast rev and fast return.

 

I've owned quite a few cars and never had one that did this. I datalogged the car to see what was happening, and what I found is that whenever you let off the throttle, the throttle plate does not close all the way. Itcloses to 7-9%, and has about a 7+ seconddecay time (it will slowly continue to close all the way during those7 seconds). This is for emissions reasons, as it is simulating a mechanical dashpot. It also does not shut off the injectors. It does it while shifting also, and is what must be causing the engine to continue revving. It's also the reason the mustang has horrible engine braking. This is with my JDM tune, which seemed to help it from when it was stock, so I don't know how much worse it is with the stock tune. Once I get my new SC pulley, I'm going to have it dyno tuned. The tuner said he can take care of that.

 

Here's the datalog you can see what I'm talking about. The first 4 were WOT then 0 throttle, without using the clutch, so there are no RPM spikes there. The last 4 were WOT then depress clutch and 0 throttle, and you can see the RPM spikes there. Sorry for the fuzzy pics, but I don't have photshop on this PC, and paint sucks for making jpg's out of screenshots.