Date:         Sun, 8 Jun 2003 16:52:48 -0700
Reply-To:     Matt Ratto <mratto@UCSD.EDU>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Matt Ratto <mratto@UCSD.EDU>
Subject:      valve cover and vacuum question -1.8 Gas conversion
Content-Type: text/plain; charset="iso-8859-1"

Hi all,

I've been driving my 1982 Westy, into which I installed a 1.8L gas motor
from an 1986 Golf (engine code GX.) It runs OK, but has poor mileage, smells
like it's running rich (but the plugs look OK,) and has a kind of loping
idle. I've screwed with the mixture, timing, and idle bypass until I'm blue
in the face but none of these seem to make much of a difference. I have
noticed that I can't get it to run very well if I time it to what the manual
says is correct - approx. 8 BTDC. (Currently it's at about 8 ATDC.) For all
of these reasons, I assumed I had a vacuum leak somewhere, but after
spraying carb cleaner everywhere I can't find any leak.

The other day I was thinking about this problem and I realized that because
of the way I had installed the engine (and removed a bunch of exhaust
equipment) the vaccuum line that connects to the top of the valve cover was
vented directly into the CIS air box (below the filter.) This is in addition
to another line also connected to the same place on the top of the valve
cover that connects into the intake manifold. (I hope that makes sense.)

In the interest of science, I disconnected the line running to the air box
and blocked it up with a piece of (you guessed it) duct tape. The car
started running differently, but before I could play with the timing and the
rest, I started hearing a funny whining coming from the crankcase. I
realized that since this engine does not have a separate crankcase
ventilation system (as far as I know) with the valve cover line blocked I
was probably creating a lot of pressure in the crankcase. Since this is
probably A Bad Thing(tm) I immediately pulled off the duct tape.

So here's my question (for those of you who have read this far): Could the
way I've connected the valve cover line be causing a lack of vacuum and
making the car run like it has a vacuum leak? If so, how should I connect
this line as to provide vacuum but not overpressure the crankcase?
Alternatively, is my hypothesis completely wrong, my troubleshooting totally
incorrect, and I should buy a honda with the hood welded shut?

any responses are appreciated,

Matt
-------------------------------------
Matt Ratto
Ph.D. Candidate
University of California, San Diego
mratto@ucsd.edu
http://communication.ucsd.edu/mratto
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