Holley 670 Truck Avenger carb help Dies!

[bosshoff]

OK. My 73 has a 302 with a Schneider cam, headers, and a Edelbrock Performer and a Holley Truck Avenger 670. My carb will allow the truck to start at high idle. It will then ramp down to low idle. If I try and raise the RPM's, it dies/sort of turns off. It does not backfire. the fuel pump (mechanical) pumps like a banshee. I think all of the vacuum lines are ok. I am not 100% sure about the carb to manifold plate/seal. I did not check this yet. What is going on? Why will it not let me drive the truck? It behaves like someone just turns it off when I press the peddle. At a high idle, it goes/sounds fine. Make sense to anyone?

 

[NC-Fordguy]

When you say high idle, I assume you mean the choke is engaged?

Low idle meaning the choke is disengaged??

Check for vacume leaks. Take a can of carb cleaner and spray around the base of the carb and around any vacume ports. If the engines rpms change when spraying carb cleaner, there is a vacume leak. Make sure all unused vacume ports are plugged

Check float levels

 

[broncnaz]

definitely check for vacuum leaks first. Also what igintion are you running and is the vacuum advance hooked up to a ported vacuum source? Next with the engine off look down the throat of the carb and open the throttle does gas squirt out when the throttle is moved? if not then your acclerator pump is jacked and is most likely the issue. Also check to make sure your choke is fully opening if it doesnt that can also cause the big stumble.

 

[dalba4]

You should be able to see the accel pump work by opening the linkage with the air cleaner off, engine does not need to be on. But you should move the choke plates to see it.

In my experience igntion system problems would be apparent were the engine under load.

GL

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