Date:         Tue, 20 Jul 2004 10:09:52 -0700
Reply-To:     Craig Oda <craigoda@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Craig Oda <craigoda@GMAIL.COM>
Subject:      Lake Trip Report and fuel pressure question
Content-Type: text/plain; charset=US-ASCII

For the first time in a few years, I had a trouble free weekend trip
in my van with a nice idle, good gas mileage, and a fridge that stayed
lit on the freeway.  Thanks to the people on this list.  :-)

My family and I stayed at Emerald Bay campgrounds on Lake Tahoe and
swam for two days in the lake.  One way distance from my house was
about 300 miles to the site.  There were a few accidents on the road,
so the driving time took about 7 hours going there, about 5 hours on
the way back.  Van idled fine in stop and go traffic.   Some points
that helped make the trip smooth:
  - bug screen in the back of the van came in really handy since there
were a huge amount of insects flying around when we go to the campsite
on the first night
  - water faucet works much better since I took it apart, sanded the
electrical contacts and put electrical contact grease on the switch
  - fridge stayed lit driving around in windy conditions since I
sealed the air leak on the side of the exhaust vent
  - cylinder misfire has now gone away since I changed a hydraulic
lifter and just readjusted a valve on cylinder 3 right before the
trip.
  - engine idles fine since I put silicone gasket sealer on the gasket
between the throttle body and the intake manifold collector
  - fuel consumption and black smoke gone since I swapped the O2
sensor and ran the engine for 300 miles with the O2 sensor
disconnected to clear out the soot from the exhaust.  This also
improved power and drivability.

So, after a successful, fun, and relaxing trip, I'm still puttering
around with the van to ensure that there are future happy trips.

My question has to do with a low fuel pressure reading on my electric
fuel pressure gauge.  The van runs fine.  However, when I don't have
the gas pedal pressed down, the fuel pressure gauge reads close to
zero.  When I press the gas down, the pressure reads close to 25 psi.
When I put the van in park (automatic transmission), the idle goes up
and the pressure settles to around 10 psi.  I have the gauge tapped
into the stock fuel pressure testing port and it's set up so that I
can read the pressure while driving.

I have a new gauge and it's possible that the gauge is incorrect.  I'm
planning to test it with a mechanical water pressure gauge hooked up
to a fuel line.  I also plan on testing the vacuum pressure.  Before I
do this, does anyone have any words of wisdom about fuel pressure?  Is
it supposed to be this low when the engine RPM is under 3,000rpm?
Even when I rev the engine, it does not go above 25psi.  Bentley says
it should be 29psi.

Here's where I'm at:
  - brand new fuel pump
  - brand new fuel filter
  - brand new fuel pressure regulator
  - tested electrical volts at the pump leads and it's okay (at least
was okay during the test)
  - pinched off fuel return line from the fuel pressure regulator with
a c-clamp and the fuel pressure immediately jumps up to 40psi or
higher.  This seems to indicate that the pump is okay.
   - took off vacuum line from the fuel pressure regulator and it
pressure goes up by maybe 5psi to about 20psi, far below atmospheric
pressure of 36psi.

Van drives fine, but I want to resolve this situation before my next
long trip.   The gauge is telling me that fuel pressure is between 2
and 15psi most of the time.  I could disconnect the gauge, but it
won't make me that much more relaxed.  Just a little.

I have bought a bunch of fuel line T's, so i can tap into the pressure
at other places to test.  I notice that if I use the old pressure
regulator, the pressure is higher...   I threw away an older pressure
regulator about 2 weeks ago.  What's the chances that three pressure
regulators are bad??

Any advice to help me make my next trip as relaxing as this last weekend trip?

Thanks.

Regards,
Craig