Took Car to the Drags and everytime I do a pass the engine dies (huge flat spot at about 5500 rpm.) the car just looses power completely then i lift my foot of the gass and it kicks back in.

I tried changing the fuel filter and the fuel pump but not change what gives????

Engine is 355 with quadrajet.

 

The Qjet float bowl is too small. I along with several other people have had that problem. Thats why I ruyn a holley , nice big bowls and no high RPM starvation.

 

How do I fix this without changing carbs?

Is there a float that can be used that is smaller and displaces less gas.

Is there a different needle and seat available that will allow the fuel level to stay high enough.

why doesn't it run out of gas on the highway when I pull out to pass someone at WOT?

 

do you have mechanical fuel pump? may be floating the pump arm. try a lighter fuel pump pushrod

 

Try going to a high volume fuel pump. It doesnt do it on the highway because you arent going from 1st gear on at full throttle.

 

sounds like it's time for a performance type fuel pump, and a regulator. Try that first, keep the fuel pressure at about 5 psi, and it shouldn't run dry on ya.

First things first, it may want to pull the carb apart and do a rebuild on it.
your float may be sticking or something, or there's a restriction in the inlet by the needle, pull it apart, make sure the tubes that vent the back of the bowl haven't fallen out.

If everything's clean and honkey dorey, then put a better fuel pump on it.

 

You can buy hi performance tuning parts for your Qjet
from Edelbrock. Try a larger (.149") needle and seat assembly.
This will allow a lot more fuel flow at a said fuel pressure
than the stock one. (.125 or smaller).
Pick up the qjet "bible" by auther Doug Roe at most speed shops
and read about modifying the bowl baffle insert for more internal fuel bowl volume too.
Get a fuel pressure guage and a fuel regulator.
Qjets don't like too much fuel pressure at idle 5-7 psi
but need 2psi+ mininum at wot at "5500 rpm" in the traps.

 

Good question Ratchet.

I just got my 355 finished a couple of weeks ago and have found that my carb goes flat about 4500rpm. It is the cc carb with the stock distributor (Accel supercoil in cap w/MSD 6AL). Do you guys think I'm having the same trouble as Ratchet? I'm no longer using the vapor canister or smog pump. My gas tank is building up a lot of pressure when the tank gets low. I just bought a vented gas cap so I don't know if this will help or not.

The larger needle and seat sounds like a good starting point. Any other ideas.

I forgot to mention I'm using the stock type fuel pump with the return line. I tried using an Edelbrock fuel pump last year with the 305 and it ran worse. After I bought the stock type it did good again.

Major parts:
350 bored .030 over with 0 deck
AFR 190 heads
comp cam magnum 270 (224/224 @ .050 with .501 lift(1.6 rockers))
Edelbrock performer rpm

Thanks,
Craig