Hi all,
For about a week now, at different rpms, at low throttle, my car hesitates or
stutters very badly, as if I were accelerating and stomping on the brake at the
same time.  It happens at anywhere from 2500 rpm to 3000-3500 rpms, in first
through third gears.  It only happens if I hold the throttle at those rpms - if
I mash the gas, it will roar through it and not stutter.  The other thing, if I
am idling and I steadily raise the rpms through that 3500 mark, it doesn't
stutter.  I also notice that it only seems to happen when the car has been
running for awhile and is warm.

I have an HKS VPC and GCC hooked up, and I think I have them properly tuned,
that is, I'm not running too rich or too idle, according to the readings I get
on the GCC.  (If anyone has the manuals to either of these, I'd REALLY
appreciate getting a copy of them, and I'll pay for 'em, too.  My mechanic
won't touch that stuff without the manuals).
The car recently was dying at idle, so I had the ICS (stepper motor) tested and
found that it's bad, so I'm having it replaced.  Would the ICS have anything to
do with this new and very irritating problem?  I also bought some fuel injector
cleaner, haven't tried it yet, though.
Thanks for any and all help or suggestions!

Al
1991 3000GT VR-4