Mike, I had similar symptoms a couple of years back with my '84.  The
culprit was a set of Bosch spark plug wires.  I didn't find the problem
myself.  Fresh out of school jr. tech at local TBA store found it.

John
----- Original Message -----
From: "Mike D." <md03@XOCHI.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, December 29, 2003 3:37 PM
Subject: More Idle Problems

> Previous History:
>   85 Automatic Westy with 150k miles.
>   Has always had rough/loping idle
>   Low oil pressure lite flickers on when warm (and rpms below 1000)
>   Mechanic recommended AFM change, but not done.
>   Had lifters replaced about 6 months ago.
>   When cold, idles very poorly, dies frequently, but would idle
>   ok when warm (still rough, but not dying).
>   At freeway speed, runs fine : can do 70mph and gets about 15-17 mpg
>   Passed smog (just barely).
>   Compression was ok (even, around 120 in each)
>   Replaced O2 sensor.
>
> Last week:
>   Mechanic put in new (rebuilt) AFM and changed Oil.
>   Mechanic said there was "a lot" of metal in the oil.
>   Drove van home (didn't run too well -- kept dying at stoplights).
>   Test drove the van the next day: wouldn't idle when cold OR warm.
>
> I tried adjusting the timing and idle screw (both with and without
> the Idle Stabilizer in circuit), but the only way to get it to idle
> was to set the RPMs at about 1200.
>
>
> Here are the leading theories:
>
> (1) My mechanic thinks the engine is shot, and can't keep oil
> pressure at 850 rpm idle, which causes the lifters to stop lifting,
> leading to loss of compression and engine stall.   This theory is ok,
> but doesn't explain why the sudden worsening of symptoms after the
> new AFM and oil change, and why now it won't idle when warm OR cold.
>
> (2) Could this be a cold start issue?  I've done the check of
> crimping the bypass hose when warm (as per bently) and the idle
> doesn't change.  Also disconnected the O2 sensory wire with no change
> in idle.  Are there any other checks to do when warm to see if the
> cold start systems are messing up the idle?
>
> (3) The previous mechanic had done some "mods" to the old AFM when he
> replaced the lifters.  I also noticed (just a few weeks ago) that one
> of the vacuum advance/retard hoses was off, so replaced all the old
> crusty looking vacuum lines.  Now I'm wondering if perhaps the AFM
> mods and the disconnected vacuum line were intentional (the previous
> mechanic's way of getting the car to idle without dying) and that by
> fixing the AFM and reconnecting the vaccum line I "broke" his fixes?
>
> (4) If it is an oil pressure problem, how quickly does low oil
> pressure cause the lifters to start malfunctioning?  Right now, if I
> set the idle to 850 it will work for a few seconds but then it
> sputters and dies.  Would lifters lose pressure within a few seconds?
>
> (5) I know that I need a new engine, but I'd like to squeeze a little
> more life out of this one.  BusDepot (or perhaps busboys, i forget)
> has a "high capacity" oil pump for $30.  Is it worth putting one in
> on the off chance it would give me a few more months?
>
> thanks again for all your help!
>
> -mike