Idle screw on NG engine

[Ben Swann]

I concur with Huw.  Check the idle switch - if not functioning consistantly, it will cause the problem you describe.  BTDT

Ben
'85 4kq


[> So, any suggestions on where to start? If I close the screw all the way t=
he engine idles so low that the oil pressure light comes on and the idle is=
 a bit rough. Also, at times my idle bounces between 800 and 1600 when the =
car is warm. If I shut it off and restart it will idle perfectly for a whil=
e=2E The problem is VERY intermittent, it may go for days at a time idling =
perfectly then have problems for a day or two. I have already "cleaned" the=
 ISV with lots of throttle body cleaner. It's nearly spotless. When 12v is =
applied, it seems to open and close fine (fast)... Any help on where to sta=
rt would be appreciated.

I would say, since your ISV is clean and presumably functioning 100%
properly (?), to take a look at your idle switch.  There may be other
factors, but something is not right, and maybe the ECU is not getting
that signal that it needs that the throttle plates are shut, sometimes.

Usually, with a warm engine, unplugging the idle switch results in an
idle around 1600 rpm or so.

You should not need to ever adjust the idle screw on CIS-E or CIS-E3
engine systems.  It's a holdover from the CIS throttle body as far as I
can tell.

Everyone, please feel free to correct me if you disagree...
--
Huw Powell]