I have a 32/36 DGAV Weber on my '77 Spitfire and had a similar problem 15
years ago when I first installed the carb. The Weber floods at fuel
pressures greater than about 3-1/2 psi. The electric fuel pump will produce
pressure that is independent from engine speed, while the mechanical pump
produces pressure that is proportional to engine speed (the higher the RPM,
the higher the pressure). At idle, you are using the least amount of fuel,
but the pump is pumping away causing the carb to flood. An in-line fuel
pressure regulator fixed the problem. You can pick them up just about
anywhere for about $14, especially places that specialize in VWs (VB has
them for $30 or $35). I have a book on Webers that recomends 3-1/2 psi, but
you can experiment with the setting.
Michael Altomare
'77 Spitfire 1500
MTAltomare@Prodigy.net
-----Original Message-----
From: Rick Gregory <rick_gregory@yahoo.com>
To: spitfires@autox.team.net <spitfires@autox.team.net>
Date: Tuesday, February 16, 1999 10:14 PM
Subject: Trouble with Weber DGAV Carb.
>
>Hi all,
>
>I've finally reached the point where I can start driving my '77 Spit
>1500 but a problem has come up on only the second day.
>
>I had the car idling flawlessly at 600 rpms for the first day. Man I
>tell you it was running so smooth and quite when I would kick into
>nuetral from 4th (when stopping like approaching a light) I would have
>to look down at the tach. so I could tell the engine was still
>running. Now, unfortunately, when I look down, the ignition light is
>on because the engine stalls.
>
>Here's what some checking has produced:
>
>1. I can't find an electrical problem (spark is good) and of course,
>compression is great on the newly rebuilt engine -so-
>
>2. I'm thinking fuel... I checked the fuel pump (which is electric in
>the trunk). I hooked it up to a gauge... 4 lbs constant pressure.
>
>Is four pounds fuel pressure okay?
>
>3. I checked the carb. This is where I think the problem is. I pulled
>the air cleaner and looked down inside... Fuel is being dumped into
>the intake (at idle) and it appears is flooding/fouling out the
>engine. I opened up the carb's bowl compartment and reset the float
>assembly (the float "level"). I ALSO INSTALLED A NEW INLINE FILTER
>into the fuel line before the carb. I also checked the little screen
>filter in the fuel inlet of the carb itself. It seemed clean. Next, I
>reassembled the carb and started the motor. It ran fantastic again,
>like before. I looked down inside the carb and it was dry, no fuel
>dumping! I then took it for a ride around the block. It ran great. I
>took it out on a main road and accelerated up to 45 mph... when I came
>to the next stop boom--> stalled again. It ran sick all the way back
>to the garage. I removed the air filter and looked and sure enough,
>excess fuel dumping again.
>
>What do you guys think? Dirt getting inside even though I installed a
>new filter? Bad float? (It is brass and is not leaking).
>
>Okay, at the risk of being lengthy how about this:
>
>I checked my back room and discovered another weber carb (DGAV 5E)
>which a guy gave me after cleaning out his garage... it was very
>similar the carb which came with my spit. I removed its float and
>needle assembly and installed them in my carb (they fit perfectly).
>(This was a plastic float) I set the new "plastic" float level and
>re-installed in my car... SAME PROBLEM! Fuel dumping! I even
>re-assembled the other carb enough to mount it on the spit and tried
>it! SAME PROBLEM on the whole new carb--still excess fuel. I finally
>gave up and re-installed the original carb.
>
>The only thing I can think of is dirt or fuel pump. I did, just prior
>to installing my rebuilt carb, flush out the fuel lines. I pumped the
>tank dry. Then I filled it with new gas... then pumped the lines until
>the new gas came out. (I never pulled the tank). And tonight, like I
>said above, I installed a new inline filter...
>
>Any ideas guys?
>
>--Rick
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