Re: 5KT : Intermittent high idle

[orin@netcom.com (Orin Eman)]

> You can cut them open and touch up the connections with a soldering iron,
> but it is a big pain to get them open.  Thanks again to Scott Mockery who
> did mine.  I would not have used that kind of force!

I don't recall opening mine requiring that much force... but anyway,
if it's broke, the worst that will happen is it will be more broke ;-).
I think I did break a plastic tab though.
Resolder ALL the connections while it's open.  It was impossible
to see the crack in the joints which were open circuit.
I used my much abused Rat Shack soldering gun both for the joints
and to spot-weld the plastic case back together...

> Anyway, replacing the ISV fixes the symptom most times and only temporarily.
> Check this switch!  BTW, it usually is an intermittant failure.  That is,
> you'll check it and it's ok.  Then check it again and it's bad.  If you need
> to assume that the ISV or the throttle switch is bad, assume it's the
> throttle switch!

You also have to adjust your idle correctly by measuring the current to
the ISV.

OH - I ALMOST FORGOT - CHECK THE IDLE SCREW!!!  The o-ring on these gets
hard and they start backing out causing an increase in idle.  This is
corrected by the ISV _UNTIL_ the idle switch goes bad when you will
find your idle is intermittantly high.

(BTW eventually, the idle screw can fall out causing a fair sized vacuum
leak and you may have problems starting.)

For those that don't want to measure the current to the ISV, set the idle
RPM to spec (800 on the 5000 CSQ) with a decent tach (not the dash tach)
(AC and all electrical consumers off) and you'll be pretty close.
I found that at the correct ISV current, I got the correct RPM.  Of course,
if your ISV is in need of cleaning, I doubt this would be the case.

Orin.