Disabling the control system might help you trouble shoot the idle issues.

I ran my '88 2.1 without the idle control system. I blocked off the
appropriate hoses, disconnected the ICU, can't recall if there was
another wire that I disconnected. The flared end of a Vanagon wheel
nut (plugged with bolt) fits into the opening on intake bellows.

I might've raised the idle a bit at throttle body but all I had to do
was let engine warm up a bit then drive. Using power steering did not
stall the engine. My van does not have AC. I timed the engine using
the "full advance" method.

With the idle control system disabled, you can ring out that portion
of harness. From what I've read though, if there's an issue in the
idle control system, its usually in the ICU itself. e.g. an over
heated component.

Neil.

On 5/16/20, Steven Mills <lefthanddrive123@gmail.com> wrote:

> Will try to be brief, but lots to the story. Have 87 Westy with idle issues.
> New items include engine bay wire loom, TPS and GW throttle body. Idle is
> low and sometimes erratic. Idle control valve does not vibrate/hum but will
> open/close on bench test. idle Control Module and valve has been changed out
> with spares I have to no avail. All grounds have been cleaned and secured.
> So, my question centers on whether or not the ECU can partially function but
> still be dysfunctional as to the idle. Any thoughts/ideas would be
> appreciated.
>
> Sent from my iPad

-- 
Neil n

VE7TBN

1988 Westy 50º ABA swap: https://tinyurl.com/yap5hpwt

1981 Westy 15º ABA swap: https://tinyurl.com/y9n4xob8

VAG Gas Engine Swap Group <http://tinyurl.com/khalbay>