Hesitation in midrange RPM

[BoostLess7mge]

while driving on the highway the other day i changed lanes to pass someone and noticed that i have a slight hesitation between 3800-4000rpm under moderate to full acceleration. in 2nd gear its barely noticeable and 3rd gear its very noticeable((f.y.i. auto tranny)). when i reach roughly 3800rpm in 3rd gear, the engine literally seems to make no power whatsoever for about 2 seconds and then the rpm's continue to rise as normal. the second time i passed someone on the highway i hit roughly 3800rpm and it hit the dead spot again and this time dropped down to 3700rpm and then continued to rise as normal. all my maintenance is up to date. could something be wrong with my ACIS? any suggestions would be appreciated!

 

[Fuzz420]

Im no expert, but it seems just about right, 3800-4200 is when the acis is activating depending on how much throttle is being applied, maybe the hesitation is the transition period.Also im not auto so i cant help you on that aspect

 

[BoostLess7mge]

ive owned the car 3 years now and its never seemed to do that before. yea that is right when the ACIS transition starts, but should it actually lug the motor down/cease power for those 2 seconds while it engages? i suppose ill check the vacuum hose that leads to the acis. ive never driven any other n/a supra so i cant compare. anyone else ever have this problem?

 

[Murd]

In your maintenances have you had the tranny properly flushed? I had the same problem on my 88 N/A auto and did this, tranny's still going out, but it caused this problem to be reduced quite a bit.

 

[BoostLess7mge]

swapped tranny and converter from a 91 turbo a few weeks ago since my old converter was whining and slipping. fluid and filter were both changed.

 

[ValgeKotkas]

Should the ACIS work the same on every gear, so I mean, why doens't it hesitate then on 2nd or 1rst gear?
Actually I dunno either, just mindstorm

 

[7MA61]

Should the ACIS work the same on every gear, so I mean, why doens't it hesitate then on 2nd or 1st gear?
Actually I dunno either, just mindstorm

Because in 1st and 2nd gear that rpm range is over very quickly

How modded is the car my car used to have a big flatspot in the midrange because the stock ecu couldn't cope with the mods and the engine rpinged its tits off and the power just plateaud.

 

[BoostLess7mge]

Because in 1st and 2nd gear that rpm range is over very quickly

How modded is the car my car used to have a big flatspot in the midrange because the stock ecu couldn't cope with the mods and the engine rpinged its tits off and the power just plateaud.

only mod i have is a K&N, and im n/a so "ringing its tits off" doesnt exist!

 

[7MA61]

only mod i have is a K&N, and im n/a so "ringing its tits off" doesnt exist!

pinging its tits off not ringing:icon_razz stupid typo.