thielepr

We have an 84 rx-12 with street port 48 deloorto setup. The problem is when we are at the track (doesn't happen in the street) and go to the left I run out of gasoline. The float are fine and we're running at 4.5 psi of gas. Any sugestions?

j9fd3s

iTrader: (3)

EFI... this is why carburators arent as good...

one of two things are happening, either the fuel sloshes away from the jets on lefts, or maybe when the fuel sloshes it closes the needle valve or something

trochoid

iTrader: (6)

How low is your fuel tank when this happens? If it happens with a half full or more thank there's a fuel bowl extension mod.

thielepr

It doesn't matter the level on the tank. It does it when the left turn is hard.

t_g_farrell

iTrader: (1)

Increasing your float level will help. Of course you have to balance the increase
with the flooding thats more possible with more fuel in the bowls.

I know mine will stumble on hard right hand turns and this is a known issue.
Adjusting the floats helps this a lot. A left hand stumble could be sloshing as
mentioned combined with weak pressure/flow of gas. Since these carbs require
low pressure (2.5 psi) to operate they need high flow to make up for it.
Somewhere upwards of 50 gph should be sufficient.

DriveFast7

iTrader: (1)

Raise the floats to 14mm when the needle just starts to seat. Keep full drop to 28mm.
Fuel pressure @ 2.5 is good like t g farrell says.

What fuel pump do you have, and does it have a return line plumbed in?

thielepr

I'm running the holely blue pump and don't have the return line

trochoid

iTrader: (6)

A return line will help the pump last longer and stabilize the fuel pressure more consistently. The Mallory 4309 is a good return style fpr, the Holley's are deadheads. It's a bit pricey running around 80 bucks but well worth it. You will also need a good fuel pressure gauge. ReSpeed sells one of the best.

thielepr

We are going to verify the float level. Also remove the rear sway bar to help with the oversteer

thielepr

We lower the fuel pressure to 2.5 from 4.5 and see a lot of imporvement on the track

installer67

iTrader: (18)

Are Dells drastically different than webers in the float size/style? My weber 45 dcoe floats are at near 8mm lightly seated. Am I that far off or are they that different?