> Patient:
>
> 1993 Cobra/125,000 miles -- stock except: shorty headers, advanced
> timing, 73mm C&L mass-air meter and an A9L processor.
>
> This combo ran solid for a number of years and the symptoms suddenly
> -- no mods or changes were made -- just appeared.
>
> The symptoms have gone on now for about 1 1/2 years.
>
> The frequency of the symptoms has slowly increased from maybe once a
> week to almost every day.  But despite the symptoms, the car performs
> well without any popping, missing, stalling, gassy smells, or smoking.
> -----
>
> Symptoms:
>
> Reved-up idle.  Sometimes.  Some days, the car will run fine all day
> long, or for a couple days.  Other days, the reved-up idle will
> continue to happen.
>
> Idle speed varies, but generally sticks -- doesn't roll -- somewhere
> between 1600-2200 rpms.  Never goes above 2200.
>
> Generally, I get the reved-up idle a few minutes -- 3-4 minutes --
> after a cold start AND after I dip into the throttle a little bit.
>
> But frequently I get the reved-up idle when/after the motor is fully
> warmed up.
>
> Miles and miles of driving -- 20-30 -- even at highway speeds, often,
> won't alter the reved-up idle.
>
> Running the car hard, even really hard, doesn't change the idle (if
> anything, it often makes it go higher up in the 1600-2200 range).
>
> Normally, running the car hard will trigger the reved-up idle.
> -----
>
> Complications:
>
> Shutting the car off and restarting _always_ fixes the idle, at least
> for a while.
>
> No codes have _ever_ popped up in the computer.
>
> Sometimes the idle will just fix itself while driving.
>
> And a few times _while reved up_ I've had it just fall to the normal
> idle speed and stay there.  And a few times, after falling to a normal
> idle, I've had it return to the reved-up idle -- like someone is
> controlling it by remote.
>
> A scan tool was run once while the idle was reved up and, for some
> unknown reason, the reved-up idle didn't return for nearly 4
> months.    Also, a few minutes _after_ the [scan] tool was
> _unplugged_, the idle dropped to normal and then a few minutes later
> it reved back up.  Coincidence?  My mechanic, and he's extremely good,
> was at a loss, but thought the processor might have some issues.
> (Note: My mechanic drive my car home that night and the car ran
> PERFECT for him.  It's about a 40-mile loop for him to drive to and
> from work.)
> -----
>
> Recent developments:
>
> A few weeks ago, I noticed on two occasions, a missing while driving/
> cruising at highway speeds.  The missing has since gone away.
>
> Also, after a cold start leaving work one day, a few weeks ago, the
> idle went below the normal idle speed and the car acted like it was
> going to stall.  After a few minutes of driving the problem went away
> and hasn't returned since.
> -----
>
> Treatments used so far, in this sequence:
>
> 1) Fuel filter
>
> 2) New TPS
>
> 3) New Air-Idle Control valve
>
> 4) New Mass-Air sensor (the actual sensor unit in the mass-air meter)
>
> 5) New A9L Processor
>
> Each treatment was used independently, but nothing has helped/worked.
> -----
>
> Besides a gun, does anyone know of a cure?
>
> Patrick