webers and fuel pressure

347 · #1 (**permalink**) 09-28-2003, 02:55 AM

Any body out there running webers?
what fuel pump and regulators are you using?
I am running a holley blue and a low pressure reg(1-4psi)
and after 30mins driving the engine starts to bog down when taking off
The pressure gage is showing 14psi
I have changed the spring and diaphram
Any suggestions what the problem may be?

427Aggie · #2 (**permalink**) 09-28-2003, 05:57 AM

Webers can only take 3 psi MAX. I run a mechanical holley with a dial type pressure regulator. If you go over 3 psi then you will blow out the seals on the carbs. I actually have mine down around 2 and it works great.

If your pressure is at the correct level there are several other things that will cause what you are having. What chokes, mains, idles, idle holders, emulsion tubes, air correctors and most important bypass jets are you runnning?

Matt

Got to love these carbs

tommyboy · #3 (**permalink**) 09-29-2003, 06:15 AM

Hello 347,
I'm running a Mallory 4070LP Gerator style fuel pump. You can regulate the fuel pressure right on the the pump housing. This is a low pressure fuel pump and comes preset to internally bypass at 4 psi. I removed my Inglese installed regulator at the carbs and only run the pump. I set my fuel pressure to 3 psi. My car runs very, very strong and no problems.

acaskie · #4 (**permalink**) 10-03-2003, 10:05 AM

With my 48 IDFs, I use a standard mechanical pump and the Inglese dial regulator set at 2.5 lbs, and have had no problems when running. In a previous webered vehicle, when I used an electric fuel pump in the trunk, I used a firewall-mounted Mallory 4207 regulator adjusted to 3lbs also to a good result.

If you have any problems with leakage after a hot shut down (out the butterfly shafts onto the manifold), a return line to the tank (to bleed off the pressure in the system after shutdown) shouyld fix that as well.