Slight hesitation at 6250 RPM?

[Nguyen Nguyen]

My NSX is a 92 with about 70K miles with all needed maintenance done. For the last 5 years, if the car is smoothly and slowly accelerated pass 6400 RPM, there's a slight (barely noticeable but it's there) hesitation (just like one lets off the throttle a bit) at 6250 RPM. Pass 6250 RPM, and it resumed acceleration as normal. It doesn't do this (or I couldn't feel it) if the car is accelerated quickly. Any idea? Many thanks!

- Nguyen

 

[MikeW]

My NSX is a 92 with about 70K miles with all needed maintenance done. For the last 5 years, if the car is smoothly and slowly accelerated pass 6400 RPM, there's a slight (barely noticeable but it's there) hesitation (just like one lets off the throttle a bit) at 6250 RPM. Pass 6250 RPM, and it resumed acceleration as normal. It doesn't do this (or I couldn't feel it) if the car is accelerated quickly. Any idea? Many thanks!

- Nguyen

I have observed the same thing with my car. I am just not quite sure if it appears at the same RPM and again sometimes it seems to be vanished. I have cleared out the a/c compressor by switching the a/c off. I have no idea but I am not concerned about it.

Reg. Michael

 

[titaniumdave]

Nguyen,
I would look for electrical problems, loose wire to the ECU, bad connection to a coil cap...something pretty simple. Maybe even a loose ground could cause enough of a voltage drop to cause a hesitation at one RPM. I use di-electric lube on all the connections to make it so things up here are less susceptible to humidity issues when we start getting rain...a slow O2 sensor might do it to, when you are at part throttle, the ECU is trimming fuel for AF control, at WOT it is closed loop running the set map.

You can always call Morgan...