On Sun, Jan 24, 2010 at 10:51 AM, mark drillock <mdrillock@cox.net> wrote:

> Not so fast. The idle valve behavior depends on the version of the FI
> wiring harness. Lots of later vans power it from the fuel pump relay and so
> on those vans it WON'T hum with just the key on, the engine needs to be
> running for it to continuously hum.
>
> Years 86/87 power it from the ECU relay and on those vans it should hum
> whenever the key is on, engine running or not.
>
>
Yes, I don't know why I put "not running" in there when I meant just
"running". Both my 90 vans have quiet ISVs when not running.

Interesting to know about the 86-87's though....

--
John Bange