need help with 70 gto

[mjgjr72]

my buddy has a 70 gto with 400 4 barrel, car is dieing out on accel and stalling at stop, think it fuel related, he has a new holley carb, inline filter and fuel pump, does anyone know what the fuel pressure should be, or what could be causeing this.

[96Civ]

You changed out the carb? I would think its your new carb if the car ran fine on the old one. You might need to adjust your float level.

[MrPbody]

Under ideal conditions, most Holleys work best with 6-6 1/2 lbs. of fuel pressure.

[69GTO]

Putting on a Holley is a down grade from the factory Carb allot of people dont like the Q-jet but truth be known most people that place Holleys on them and end result is that they flood. Because they over carburate. A properly tuned Q-jet will do anything that that a Holley does and better IMO.

[MrPbody]

Simply installing a Holley is not the problem. While I agree the Q-Jet may be the best factory-developed carb in the history of cars, a Holley is not a problem child. Installing one with the wrong jetting is the fault of the installer, not Holley. If power production is the primary function of the car, you can't beat a Holley. For efficiency and drivability, along with good power production, Q-Jet is a better choice.
You would be amazed how many people have thrown their Q-Jet away, calling it "Quadra-FLOOD". The problem is not the design, but the float. They're fibre floats, and need replacement EVERY time you open them up. I use NAPA brass replacements. They cure that problem.
Another unpopular issue with Q-Jet is the size of the fuel bowl. It simply can't hold enough fuel to get a 550 horsepower engine through a 1/4 mile.

So, when this car isn't running properly, is there any sign of smoke, either blue or black? Does the coolant temperature change when cruising down the highway?

[mjgjr72]

it has been fixed the filter sock in the tank was clogging up with rust

It's been said (so I have heard) that if you want to get every 10th out of your car at the track you run a Holley, and if you want to drive your car and not have to tune your carb all the time you run a Q Jet.

Tho Holley kinda fixed the problem with blowing the power valves during a carb back fire, I still find that the carb has "to many things to go wrong" with it for say looking at a Edelbrock.

It's hard to pass up the EDL. 800cfm carb as well as the new thunder AVS carbs.

I think that Edelbrock should come out with a carb that is the same or better then Holleys big boy Dominator.

I also think that Edelbrock should ditch the "factory" like PCMs in the EFI program with the "6 chip" fits everyones engine. The units they sell even look like factory "buched" units.