[Supras] Idle cutoff cycle

[Christian, Skip]

Bernie/All,

	I disconnected the ISC valve on mine - no difference.  Even
tried opening & closing it all the way to see if the computer would
immediately return it to where it should be for idle - it didn't.
Finally replaced it - no difference.  If disconnecting the ISC doesn't
help, its not the ISC (idle speed control valve).  I do not think the
valve can respond quickly enough or far enough to cause the problem you
have.  Computer seems to be able only to open or close it one or two
steps, which only changes RPM by about 200-300 (if that much).  Its
there to fine tune the idle speed, at least on the N/As.  The valve, on
N/As does not step up the idle when the engine is cold.  On N/As, this
is handled by an increase in ignition advance of about 10 degrees.
	Really recommend you remove/disconnect any fuel related mods
that are functional at idle speed.  After disconnecting each one, cut
power to the computer to clear the memory, then start car and take it
out for, at least, a 15 minute drive to build up some data in the
computer.  Then check the idle.
	Does your's do the same thing (or similar thing) when the engine
is cold ??  Mine did.
	What mods do you have ???  This is the key (or there would be
more cases of this problem).  Dealer didn't have a clue as to the cause
- I asked the lead (most senior) service person.
Good Luck, Skip
P.S.  I only have E-Mail at work, so I'll be gone from around 2:30 today
until 7:00 Mon.  Sorry, for the rambling, I'm an engineer.........