ISV valve-OK, not OK

[Myke456 <Myke456@aol.com>]

Symptoms (87 5kcsTQ):
Idle slightly high, 1k when warm.
Revs "hang" for a second before dropping during norm driving/shifting.

Removed ISV, sprayed carb cleaner in both openings, jiggled/drained/repeated
5-6 times. Also sprayed, hooked up and turned ign. on/off a few times. Blow
out allow to dry before reinstalling.

Results:
Idles nice at 800
Revs drop back immediately after letting off gas
but, only last 1-2 days. Entire procedure done twice, same results.

Questions:
Is there a more complete cleaning/testing method?
This indicate time for replacement of this orig. part?

Thanks,
  ([____]=====OOOO=====[____])   87 5kcsTQ, 218k miles
 []]]]]]]][Mike Aiello][[[[[[[]     original owner
___\}}}/________________\}}}/_______myke456@aol.com
       Dutchess County, NY