Date: Thu, 1 Sep 2005 21:07:29 -0500
Reply-To: Stan Wilder <wilden1-1@SBCGLOBAL.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Stan Wilder <wilden1-1@SBCGLOBAL.NET>
Subject: Re: Aircooled Running Problems
Content-Type: text/plain; charset="iso-8859-1"
There are some other things that might cause the problem.
Cylinder head temp sender under the Driver side intake runner.
Thermo Time switch in the same area.
You could also have a distributor vacuum advance diaphragm leak.
You could also have a deceleration valve leak or a leak in the line going to
the vacuum booster.
In addition I've seen point sets screwed in with long screws that locked the
advance weights of the distributor or distributor advance plates that were
locked because of long screws in the condenser mount.
The vacuum port on the throttle body can get clogged (push a hat pin or
other thin wire in to clean it.)
Stan Wilder
Engine Ceramics
214-352-4931
www.engineceramics.com
----- Original Message -----
From: "Thompson, Michael" <Michael_Thompson@GOLDER.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Thursday, September 01, 2005 8:28 PM
Subject: Aircooled Running Problems
Hi all
I have a strange running problem with my 1981 aircooled westy. The vehicle
starts and runs fine, with correct idle. However, when blipping the
throttle when parked, the engine hesitates as if mis-firing until the RPM
gets high enough and then it revs okay (maybe 3 seconds). When driving,
this is shown as 'hopping'/bucking when accelerating at partial throttle, or
when decelerating at partial throttle. If the throttle is opened wide, the
bucking stops after 2-5 seconds and the engine runs normally on the highway.
In addition, power is down on hill climbs and the fuel milage is a low 14
MPG on a highway run at 70 MPH. All 4 spark plugs have black sooty coating
suggesting rich running, and when the throttle is blipped after idling for
10 seconds black smoke comes from both exhausts (EMPI).
The problem is I have checked/tried virtually EVERYTHING using the
ProTraining Manual and Bentley. The entire ignition system, including
distributor is brand new and timing has just been set. I have checked
everywhere for leaks in the injection system and can find none. I have done
all electricall checks on the AFM and it checks out fine within spec (I even
pulled the cover and everything looks well inside). I have checked the cold
start valve, the fuel pressure (only 1psi above the high end of the
acceptable range), injectors and resistor impedence (9.2 ohms compared to
approx. 7 in Bentley), the head temp sensor is new and I have checked it
electrically as well.
I have not checked the injectors for leaks as all 4 plugs are sooty and I
would be suprised if all the injectors went at once. All I can think of is
the computer, although my understanding is that they are incredibly reliable
and don't go wrong ofter.
HELP PLEASE - I can't think of anything else to check, and I don't have a
spare computer.....
TIA
Michael