I suspect 2 things...

- fuel pressure regulator -> self explanatory

- at least one leaky fuel injector...-> when the engine id shut of, the
injector(s) keep dribbling, so the cylinder(s) collect a small amount of
gas which in turn give a very rich start up....

On Sat, May 16, 2015 at 10:10 AM, Larry Alofs <lalofs@gmail.com> wrote:

> It seems to me that if the fuel pressure leaks down too quickly, the cause
> could be an injector, the fuel pressure regulator, or the fuel pump.  The
> first case is more serious than the last two.  You need a way to tell which
> it is.
>
> Larry A.
>
>
> On Sat, May 16, 2015 at 11:35 AM, Stuart MacMillan <stuartmacm@gmail.com>
> wrote:
>
> > Easiest way to do the fuel leak down test is with a fuel pressure gauge.
> > Bentley says system should hold pressure (30 psi or so) for several
> minutes
> > after shutdown.  If your gauge comes with an open hose adapter, slip it
> > over
> > the fuel tap near the distributor, and use a clamp.  Otherwise cut it and
> > splice it with a brass barbed coupling for other cars. Get the type that
> > drains any residual gas out a separate line. Instructions here, including
> > safety procedures: https://www.youtube.com/watch?v=QsqBJxKj1KQ
> >
> > Do it soon, backfires are hard on the AFM. I've used mine many times over
> > the past 40 years to diagnose fuel system problems.
> >
> > Stuart
> >
> > -----Original Message-----
> > From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
> Of
> > Dennis Jowell
> > Sent: Saturday, May 16, 2015 3:19 AM
> > To: vanagon@GERRY.VANAGON.COM
> > Subject: Start up,back fire?
> >
> > Question on why do I sometimes get a backfire from my 2.2 GOWESTY WBX.
> > yesterday I drove the 88 gl Westy an 1.5 hr pulled over to check my GPS,
> > shut the engine off. Then 2 minutes later started it and "bang" it
> > backfired, it did start. Shut it down and tried again same thing. Drove
> > home
> > it didn't occur again. Any thoughts of what is going on? The new  Engine
> > has
> > about 5000 miles on it. Maybe to many mice running around in there.
> >
> > Dennis Jowell
> > Scotch Hollow Farm
> > Newbury, Vermont
> >
>