I recently picked up another 78 ford bronco it's been sitting since 1997 and after a rebuilt carb and a new fuel pump it fired up. But now it will idle perfectly fine but once u start revin past idle it starts to miss and the rpms barely climb. But then it will clear up and run like a top till u get to about 3 grand on the rpms. I've changed plugs wires cap and rotor and pick up coil and even rebuilt the carb again and adjusted the float and I'm out of ideas on what to check

 

what kind of carb?

 

Just the factory 2 barrel

 

Did you replace the fuel filter? When you rebuilt the carb, did you soak it in solvent and blow out the internal circuits with air?

How's the accelerator pump...working as it should?

Have you ruled out vacuum leaks, put a vac gauge on the engine?
Is the choke working as it should?

Sorry for all the Q's. I'd assume that you did all of the above, but sometimes it's the most obvious thing that will get ya.

I had a 2150 that was cranky as the day was long...it'd spit and sputter, got tired of it.
I replaced it with an Edelbrock 1406 and a 2171 intake...much nicer.

 

Yes I replaced the fuel filter 3 times and replaced the accel pump and it's working fine. And the choke is working as well. I didn't put a vacuum gage on it bc I don't own but all the hoses r hooked up to the factory locations and replaced any hoses that were questionable and even sprayed a little starting fluid around them to check for leaks.

 

How about the soft rubber portions of your fuel line, replaced those?

Tank to hard line, there's another one inside the frame rail just under the drivers door, and of course the line connecting to the fuel pump/from the pump hard line to the carb.

The rubber lines can collapse under pressure/demand and cause starvation problems or
they can dry out and crack causing leaks.

 

Yes I also checked those and also ran a new rubber line from the fuel pump straight to as gas can and still had the same trouble and I also replaced the fuel pump it's self.

 

And I also ran a new hard line from the fuel pump up

 

I also romanced cap rotor plugs and wires on it and checked the timing aswell

 

Sure sounds like a vacuum leak, probably a cracked vacuum hose somewhere.

 

I like my ol Bronco alot but I have never romanced anything on her.

 

Liar, I have video of you romancing your Bronco

 

You were'nt supposed to tell anyone that