Date: Fri, 16 Aug 2002 22:59:54 -0500
Reply-To: tmarciniak@WI.RR.COM
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Tim Marciniak <tmarciniak@WI.RR.COM>
Subject: Re: Loss of Power False Air Oil Breather?
In-Reply-To: <00ae01c24579$c20015a0$6801a8c0@gumby>
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Here is more on symptoms:
Van starts fine. When I press on the accelerator there is a
hesitation before rpms increase on the tach, maybe a 1/2 second or
so. This happens if engine is cold or warm. Normally when I press on
the accelerator the van is very responsive immediately. It idles at
800rpm but it does not sound right, it sounds like it is missing to
me but when I pulled the old spark plugs they looked ok to me, light
tan to gray, they were not carboned up or oil fouled, I concluded no
ignition miss, has to be something else. It does not stall. Sound
out of the tail pipe is not right. I guess the most obvious thing is
the hesitation on acceleration and somewhat lumpy thumpy idle sound
from the tail pipe whe I stand near it and listen attentively.
Usually the exhaust sound is very pleasant to my ear when its running
right.
Another thing to mention, about two weeks ago we went camping with
the van. Two days before we were to leave the metal water pipe on
the drivers side of engine that goes from thermostat housing to water
pump springs a leak. The day we are set to leave I replace this pipe
and off we go on a 3.5 hr drive up to Northern Wisconsin. The only
electrical connection I disconnected was the temp sensor from the
thermostat housing when replacing this pipe. Van runs fine all the
way, I did note that it was running slightly cooler than usual, just
below the red LED. So 10:30 PM we pull into the park we are camping
in to check in at the park office. Van is off maybe 10 minutes. We
come back out it starts up I go about 10 feet and cant get the rpm to
go much over 2000 and it stalls. I'm really confused now becasue it
just ran wonderfully for the last 200miles. So I sit and let it idle
erratically for a few minutes and then the idle finally smoothes out
and I book for our campsite--what a way to start a 5 day camp trip.
The following morning I start the van just to see how it sounds and
its running but not its usual perfect self. So I open up the engine
compartment and start to check things out. I immediately find the
braided ground strap that goes from the block to the gound point near
the coil is almost split, so I secure with some duct tape and hope
that will hold till I get home--it did. I also disconnected the O2
sensor to see if that helped and it seemed to. I drove the van for
the next five days and it got us back home 65mph all the way. A
little nerve racking but the van ran pretty good considering the
initial problem I had our first night up north.
When we get home from camping the first thing I do is replace the
ground strap. At this point I think the van was running fine but I
cant be positive now. About 3 or 4 days ago I noticed this
hesitation and thats when I did the tuneup and started poking around.
Last fall I put a new exhaust system on the van including new O2
sensor and catalytic convertor. It has run fine all winter, spring
and summer and only since the camping trip has it started to act up.
Because the vanagon is so under powered I sometimes mistake a real
problem for its assumed lack of power or vice versa. Its when I
really stop and listen that I pick up on problems like this one. The
van has 100k miles on it and all maintenance has been done by me with
the exception of the heads that were replaced at 70k by a very
competent vanagon mechanic.
I have not measured fuel pressure yet thinking it was ignition system
related. Nor did I check ignition timing or even play with that in
two years.
Thanks for your reply as I contemplate my next step.
Tim Marciniak
90 Multivan (Automatic)
>Tell us more about the symptoms and less about the things you did.
>Loss of power when? Under load? On acceleration? All circumstances?
>Does it idle correctly?
>Is the fuel pressure correct?
>When did this loss of power start, all at once following some DIY
>futzing, or gradually over time? If it started all at once, what did you
>do just prior? If gradually, what has been different in the
>circumstances lately? Hotter weather? New gas station? New teen driver
>with access to the Van? Carrying an 18-ton commemorative anchor from
>your trip to the USS North Carolina Battleship Memorial?
>
>From the tiny bit you described, I'd guess the timing is off, you have a
>clogged filter (could the air filter have gotten wet?) or your Catalytic
>converter is melted/fused and plugged.
>
>Developing business and guiding change since 1996,
>
>G. Matthew Bulley
>Bulley-Hewlett
>Marketing & Communications
>Business: www.bulley-hewlett.com
>AIM = IExplain4u
>Phone: +1.919.658.1278
>
>
>-----Original Message-----
>From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM] On Behalf
>Of Tim Marciniak
>Sent: Friday, August 16, 2002 4:31 PM
>To: vanagon@GERRY.VANAGON.COM
>Subject: Loss of Power False Air Oil Breather?
>
>New problem just cropped up for me with my 90 Vanagon. I seem to
>have a significant loss of power both when engine is cold and warmed
>up. Recent maintenace included replacing the ground strap from block
>to ignition coil, cleaning up contacts on the ignition coil, new
>rotor, distributor cap, new spark plugs and wires, new air filter,
>recent oil change. Checked throttle position switch and this is ok.
>Idle stabilizer is working. I then checked for vacuum leaks and
>replaced vacuum line from fuel pressure regulator to intake manifold
>because this line looked suspicious although I think it was ok. Next
>I pressurized the intake system with air found a leak coming out of
>the oil breather pipe. This is the large black plastic pipe that
>sits on top on the engine with a line that goes from it to the air
>intake hose just after the AFM. This black breather pipe is not
>supposed to be vented in anyway to the atmosphere---Correct? Because
>of this I suspect I have an air leak into the intake system after the
>AFM (false air) which may be leaning the air/fuel mix. Has anyone
>had problems with this pipe? Mine seem to be leaking near the top
>ridge just under what looks like a cap on this pipe but it is not
>removable from what i can tell. Any suggestions appreciated.
>
>TIA
>
>Tim
>--
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