Date:         Thu, 13 Jun 1996 07:23:00 -0400 (EDT)
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         Porter_Fred%PAX9@mr.nawcad.navy.mil
Subject:      RPM oscillations when cold


Hello,
Whenever I start my 87 vanagon, and the engine is cold, the idle will 
oscillate from about 600 to 850 RPM and is rough.  This morning when I 
started it, I pressed lightly on the accelerator to increase the RPM to 
about 1400-1500 range and then held it steady.  The RPM would then oscillate 
from 1400-1500 down to 950-1000 and then back up.  When it swings thru 
950-1000 it is also somewhat rough.  I didn't time the period, but it was 
regular.

After I pulled out and set off to work, but before the engine completely 
warmed up, it runs very rough.  Hesitates when I accelerate from a stop, 
then charges.  When in 2nd/3rd cruising thru the development at 25-35 mph 
the engine is not responsive to gas pedal inputs.

When I got to work, a 15 minute drive, the engine was warm:  temp needle 
centered in the gauge.  The idle was stable at about 750-775.  I know this 
is lower than the Bentley manual says it should be, but it was stable.  Then 
I repeated the increased steady RPM.  Accelerated the engine to 1400 rpm and 
no oscillations.  Hmmm.

What is it that would cause the idle to oscillate so when the engine is 
cold?
If anybody on the list is an VW/digifant EFI guru, I'd really appreciate any 
advice about trouble shooting this anomaly.

Thanks,
Fred Porter
porter_fred%pax9@mr.nawcad.navy.mil
relax and spin
87 syncro