sgtjd
Well-known member
I have a 1973 Mach 1 with a 351 Cleveland Engine, H code.
The intake is an Edelbrock intake manifold dual plane for a 4 barrel carb
The carb is a Holley 460. Its probably about 30 years old.
I have new ignition parts everywhere: Petronix II, new rotor and cap, new spark plug wires and spark plugs etc. etc.
Timing and starting the engine are fine.
No vacuum leaks. The engine idles great.
Problem:
When I initially push on the accelerator I get a slight hesitation. However when driving at 30 mph or above there is no hesitation due to the rpm of the engine and when I fast accelerate/kick down no issues.
Also before it warms up I’m getting some misfires thru the carburetor like its not getting enough fuel or something and the car slows down from the loss of power. I checked and adjusted the carb with a vacuum gage and I’m getting a reading around 46-48 on both sides. Also when I accelerate the carb by hand when its warming up I get like a backfire thru the secondary’s like I stated before. However, after its hot and running for down the road for 10 min. I don’t get the misfires but it still hesitates on acceleration. I also check the fuel pump and the pressure is fine.
Solution:
I don’t know which is best either to do a rebuild or replace the carb with:
1. Holley Carburetor 4V Electric Choke 600 CFM Polished Finish 1965-1985
a. Holley Part Number: 0-80457S
2. Holley Carburetor 4V Electric Choke 650 CFM Classic Finish 1965-1985
a. Holley Part Number: 0-80783C
3. Holley Carburetor Street Avenger 4V Electric Choke 670 CFM 1965-1985
a. Holley Part Number: 0-80670
4. 600 CFM Four Barrel Street Carburetor
a. PART #: 0-80452
5. 650 CFM Four Barrel Street Carburetor
a. PART #: 0-989`5
The intake is an Edelbrock intake manifold dual plane for a 4 barrel carb
The carb is a Holley 460. Its probably about 30 years old.
I have new ignition parts everywhere: Petronix II, new rotor and cap, new spark plug wires and spark plugs etc. etc.
Timing and starting the engine are fine.
No vacuum leaks. The engine idles great.
Problem:
When I initially push on the accelerator I get a slight hesitation. However when driving at 30 mph or above there is no hesitation due to the rpm of the engine and when I fast accelerate/kick down no issues.
Also before it warms up I’m getting some misfires thru the carburetor like its not getting enough fuel or something and the car slows down from the loss of power. I checked and adjusted the carb with a vacuum gage and I’m getting a reading around 46-48 on both sides. Also when I accelerate the carb by hand when its warming up I get like a backfire thru the secondary’s like I stated before. However, after its hot and running for down the road for 10 min. I don’t get the misfires but it still hesitates on acceleration. I also check the fuel pump and the pressure is fine.
Solution:
I don’t know which is best either to do a rebuild or replace the carb with:
1. Holley Carburetor 4V Electric Choke 600 CFM Polished Finish 1965-1985
a. Holley Part Number: 0-80457S
2. Holley Carburetor 4V Electric Choke 650 CFM Classic Finish 1965-1985
a. Holley Part Number: 0-80783C
3. Holley Carburetor Street Avenger 4V Electric Choke 670 CFM 1965-1985
a. Holley Part Number: 0-80670
4. 600 CFM Four Barrel Street Carburetor
a. PART #: 0-80452
5. 650 CFM Four Barrel Street Carburetor
a. PART #: 0-989`5