Date: Tue, 5 Oct 2004 06:40:20 -0500
Reply-To: Al and Sue Brase <albeeee@MCHSI.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Al and Sue Brase <albeeee@MCHSI.COM>
Subject: Re: update - Rocky's results - was Westy Karma,
was stuck in Custer
In-Reply-To: <E1CEhIB-0005c3-00@smtp01.mrf.mail.rcn.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Joy:
The black smoke and choking off at idle definitely do not point to
LACK of fuel delivery. The measurement of 40 psi is too high, too.There
ares only a couple of things that could make it that high: A bad fuel
pressure regulator (likely), a lack of vacuum signal to keep the
regulator at the cruise setting (easy enough to determine without any
tools), or a blocked or kinked return line to the tank (not likely, but
also easy to check for kinks just by following the route of the line
back to the tank.)
The fuel pressure regulators at some point will leak internally and
route fuel back thru the vacuuum line into the intake manifold making
the mixture richer yet. I think this is what is happening. It may be
possible to see that the inside of the vacuum line is wet. In an
emergency one could just pinch this line off and make things somewhat
better.
These fuel pressure regulators do fail. Getting a new one is not a
bad idea.
BTW, if you are ever concerned about the condition of the o2
sensor, it is easy to just disconnect the single wire- the engine will
run pretty good without it. I've gotten about 15-16 MPG with it
disconnected. This is absolutlely necessary if you get an exhaust leak
ahead of the oxygen sensor. Disconnecting it will put it into a limp
home mode much more like the only mode available on an earlier air
cooled injection. It still works, just not as accurate as the system in
closed loop.
I think that in the 200-300,000 miles that I've driven 2.1,
Digifant equipped Vanagons, I've had only 2 bad oxygen sensors, one bad
fuel pressure regulator, and one Vanagon syndrome (repaired with the VW
harness). Plus the current problem with a rusty gas tank, which pretty
much I blame on a previous life in Pennsylvania.
Not bad for 14 years of ownership. Never had a failure of a major
electrical part of the FI system, Or of a fuel pump and that holds true
clear back till 1982 when I got my first Bosch equipped type 2 VW, a
1978. NEVER a fuel pump failure in probably 400,000 miles. I guess
maybe Rocky's right about taking a spare- not likely necessary.!
I should add, that even though this is frustrating, sometimes the grass
is not so green on the other side of the fence once you get there! Other
makes of cars/ vans/ SUV's have their share of problems, too and not
always inexpensive to fix. And no sense of fraternity/ support from the
Vanagon list either!
Al Brase
Joy Hecht wrote:
>Hi all,
>
>Thank you everyone who sent ideas on what's bugging Matilda. You mostly
>seemed to think that it was fuel pump/fuel filter/clogged fuel hoses. A few
>votes for my oxygen sensor. I replaced that three weeks ago (though I don't
>think I needed to), so it's not the problem.
>
>Well, so far this is the mystery problem. I got towed into Rapid City this
>morning, and Matilda and I are now resident with Rocky at Import Service.
>(Greetings from Rocky to you, Larry C. and Frank C. and Frank's friend Ina.)
>
>Rocky spent six hours trying to diagnose Matilda's problems and so far has
>not succeeded. Things he tried (not entirely in this order):
>
>- check fuel filter, little screen inside fuel pump, hoses from gas tank to
>fuel pump to fuel filter. All were clean.
>
>- check gas coming out of tank. Clean, no crud.
>
>- check fuel pressure while driving. Too high, 40 (units?) while driving.
>Running too rich, black smoke coming out, lots of misfiring and lurching and
>stuff like that.
>
>- check air flow meter. Swapped out my air flow meter for another one, went
>driving with that. No change in fuel pressure, black smoke, etc.
>
>- put resistor (??) on air flow meter to check if I have intermittent
>Vanagon problem. Went driving. No change.
>
>- checked temperatures all over the place. Found that the big coolant line
>into the thermostat was hot and the big coolant line out of the thermostat
>was cool. Replaced the thermostat. Went driving. Made no difference. If
>thermostat was bad and coolant wasn't heading up to radiator to cool, I
>don't understand why my engine has never overheated. And occasionally the
>fan does go on. The needle never shows the engine to be hot. Rocky hasn't
>yet checked if the hoses are now the same temperature as each other - gotta
>remember to do that tomorrow. Of course if I didn't need that thermostat,
>it would now cost more to remove it and replace my old one that to just
>leave it there.
>
>- replaced heat sensor near fuel injectors, which was no good (he said).
>Made no difference.
>
>- swapped my fuel pump for another fuel pump. Fuel pressure dropped to 15.
>Didn't even try driving.
>
>- swapped for a second alternate fuel pump. Fuel pressure went up to 22.
>Tried driving, no power at all.
>
>- checked that hoses from fuel pump to gas tank were clear. They were.
>Went driving (with second alternate fuel pump), fuel pressure back up to 40
>and black smoke, no changes from the original situation.
>
>- swapped computer for another one. Went driving, made no difference.
>
>I think that was it for today, as far as I can recall. The next hypothesis
>is that I need a new fuel temperature regulator. Rocky ordered one of
>those, and also a new fuel pump, just in case either fixes it. So that's
>where we start tomorrow morning.
>
>
>
>
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