Hesitation, stutter.... TSB complete... now what?

[RMC_SS_LDO]

I've noticed something odd when accelerating and wondered what the deal is.

I had the 1-2 WOT shift hesitation TSB completed (in June actually) and it works fine, this is not the issue at hand. I am seeing a hesitation when accelerating just before any shift (1-2, 2-3 wherever) but not at WOT. It seems to show up if I'm at about 80% throttle. It almost seems like it is stuttering or bouncing off of a rev limiter, but it is still well below red-line and again, it does not do it at WOT.

I noticed it a couple of times when I would accelerate at WOT and then back off the throttle just before a shift. It seems to consistantly hesitate at other than WOT (I'd guess 75%-90%). I'll try to monitor it in EVIC to nail down the specific throttle position.

Any ideas?

[1fastsedan]

See if this describes the problem you're having:

Mine was inconsistent and threw no codes so it was a b*tch to figure out. It would vary from a minor pause or stutter all the way to a full on buck as if you forgot to put the clutch in on a manual. It usually happened after I would get on it at 75-80% throttle and then have to back off for some reason (someone entered my lane, light change, etc.).

It was pretty much all fixed with a new crankshaft position sensor.

Luckily, a buddy of mine works at a dealership and said that they have seen a few fail on the 5.7 motors so we thought to look at it.

[RMC_SS_LDO]

Originally Posted by 1fastsedan

... It usually happened after I would get on it at 75-80% throttle and then have to back off for some reason (someone entered my lane, light change, etc.).

That's pretty close, but to clairify it happens when holding at near WOT vice backing off prior to the gear shift. If I read you right, you were rolling off the gas and it would do it- not the case here.

Think of a WOT run, but instead of WOT hold the throttle at 70%-90% and allow the car to shift. Just prior to the shift, it causes the car to hesitate and buck; it feels like fuel is being cut or something like hitting a rev limiter but it's still below redline.

[1fastsedan]

I think we're talking the same thing. When you back off of the 75-80% throttle, the car comes out of "sport shifting" mode or whatever its called where it shifts near red line and back to tame shifting mode - so it shifts when you lift.

It could also be the computer pulling timing for the shift. The PCM and TCM are programmed more for long tranny life than 100% performance. If you're planning on getting a Diablosport Predator handheld tuner, you can wait until after you've played with the TCM settings (line pressure, torque management, shift points, etc.) before trying the crankshaft sensor.

[Kidrock73]

anymore news on this? i seem to be having a similar problem. 1-2 shift TSB done, thats fine. what im seeing is when i get 80-90% throttle the 2-3 shift is that bucking, bouncing off the rev feeling you desribed. kind of a stutter, but its well below redline. it just falls on its face it seems pretty consistent, with 3 stutters and then it shifts out back to business at hand. this is on steady throttle, Not backing out. (thats another issue) it seems to do this everytime i really jump on it. and only on the 2-3 shift. this problem only started to occur after i had the TSB done for the leaking tranny o-ring. in which they told me that they do not just replace the o-rings, but now they replace the entire "plug" he called it. at least theres no more tranny leak it just shifts like junk now !!!!


to the issue of " backing out " of the throttle before a shift, at 80-90% throttle. several times mine has hung in gear, after backing out. (due to different circumstances) resulting in me having to tap the autostick to get it to shift out. for example, the other morning i had to get a bit AGGRESSIVE entering an on ramp, so i jumped on it just for a second, backed out to merge in and its hanging at 5000 rpm, steady hanging, im waiting for it to shift, but no. so i tap the autostick once , evic shows 3rd gear. tapped it again, finally it shifts out. back to normal. kinda wierd. it has done this several times. i just cant figure out why it does this.

anyone else having these kinds of tranny issues? if so what have you found out. thanks

i might have to result to going to the stealership!!! lol