You can install a fuel pressure regulator in line between the fuel pump and
the carbs to reduce the pressure. Most are factory set between 2.5 to 4
pounds of pressure. The better electric fuel pumps will have a preset
pressure shut off switch that will cut the power to the pump once the
pressure has been reached and will restart when the pressure drops below the
preset. This saves the pump and the carbs. The newer high pressure fuel
pumps are continuos run to maintain a higher pressure for fuel injectors and
require a return line that is opened by a pressure regulator to "bleed" the
excess fuel back to the fuel tank. But these types of pumps are running
around 35psi for proper fuel spray at the injector tip.
Your problem sounds more like an improper float setting or something is
obstructing the complete closure of the fuel needle. Try resetting the
float height a little bit less than factory spec and see if this doesn't
help.
Larry Zink
Z Group Racing and Performance
Houston, Texas
-----Original Message-----
From: George R. Parker <gpark@crosslink.net>
To: triumphs@autox.team.net <triumphs@autox.team.net>
Date: Monday, November 30, 1998 1:51 PM
Subject: tonneau snaps and SU carbs
>
>Hi List,
>
>I've seen the post about the "lift-the-dot" fasteners on tonneau covers. I
>have a '78 Spit and bought the tonneau after the car (I think from TRF).
>My dash has 4 "posts" and the cover has the corresponding open rings (what
>the original poster referred to as "grommets"???). This works fine for 90%
>of my use, but in the fall and spring, I'd like to drive with the tonneau
>on. However, over 50mph or so, the wind buffets the cover enough that the
>*leading* edge lifts off of the posts. I've often thought of changing it
>to the "lift-the-dot" type fastener, but don't know how difficult it would
>be to change the tonneau itself (changing the posts on the dash would
>probably not be that big a deal). I've also thought of trying some clip on
>the posts to hold the tonneau in place. Any thoughts as to what might
>work? I'm thinking just a tiny binder clip to hold it on while I drive.
>
>On another note - My SUs are still leaking fuel. This time through the
>vent pipe. Is it possible that the fuel pump is "overpowering" the float,
>essentially "sinking" it, thus allowing the fuel to flow? The SUs (HS-4s)
>have Grose-Jets installed. Last night I applied sealer to the gaskets and
>threads of the Grose-Jets. What do I do if the pump (replacement
>mechanical) is, in fact, pumping at too high of a pressure?? Are there
>aftermarket electric pumps that shut off when a certain amount of
>backpressure is sensed? I know the old SU pump on my Dad's XK-120 works
>that way, but all of the electric pumps I've seen are continuous running,
>thus requiring a fuel return of some sort (a provision *not* on my SUs).
>I'm starting to regret ever getting rid of that Weber...
>
>Thanks for any insight you may provide,
>
>George P.
>
>
>George R. Parker | THINK -
>AHNTECH, Inc. | It's good practice for when
>(540)663-5936 | the computer goes down.
|