'87 5ktq--no idle

[Wallace White]

Hi Mike -

I've had that happen once or twice myself, but it's always been present
right at startup; it usually lessens within ten or fifteen minutes of
driving. The other symptom has been the off-throttle behavior: as soon
as I lift off the throttle, the revs would plummet. (Normally, they
float a little and drop more slowly.) I figure that adds up to a
sticking ISV. Need to make a pick-n-pull run myself.

I like the theory that the ISV's connection is intermittent, disabling
it. Did your off-throttle behavior match mine?

- Wallace
   '87 5kcstq 188k

P.S. Hope to see you at Monterey next Sunday.

Mike Veglia wrote:
> 1. The engine was running perfectly--just no idle. Good (normal) boost,
> smooth, easy to hold 800RPM with the throttle. Because of this I'm
> suspecting it is not due to a serious vacuum leak that would usually have
> drivability problems associated too.
>
> 2. After getting home I shut it off to switch parking spots (put the 5ktq
> into the "storage spot" and the 4kq into the "daily use" spot in the
> carport). Upon restarting all was back to normal (good idle). Strange, but
> due to time constraints...it gets the "parked" punishment anyway ;-)
>
> 3. I did briefly pop the hood. While idling away as if there were nothing
> wrong I disconnected the ISV cable--it died immediately, same as in the
> failure mode. Upon reconnecting the plug into the ISV the idle did not
> return without shutting down and restarting (hmm, sounds like Windows).
>
> So, based on the above my initial theory is bad electrical connection at the
> ISV plug, or bad ISV, or WOT Switch, or ????? I was thinking about a
> Pick-N-Pull run this Sunday anyway, perhaps I'll get lucky and find a
> suitable substitute ISV there cheap to try.