Trucks backfiring

[kingbronco]

My bronco is backfiring through the carb when i give it full throttle. It sits and idols fine and will rev up with out a problem when its at idol. When i drive down the road its fine but when i go above 3/4 throttle to full throttle it backfires and runs poorly till i back off the gas anybody have any ideas. ( I have the timing set at 8btdc per my emission sticker)

 

[Yardape]

Can you give a brief short recent history of your truck? What have you done to it in the last little while. Sounds like a timing issue to me.

 

[white night]

what kinda carb do you have?

 

[kingbronco]

The most recent things I've done is i put a edelbrock performer intake and a edelbrock performer 750CFM carborator and I'm about to do plugs wires cap and rotor tomorrow when it decent outside.

 

[white night]

The most recent things I've done is i put a edelbrock performer intake and a edelbrock performer 750CFM carborator and I'm about to do plugs wires cap and rotor tomorrow when it decent outside.

how long ago did you put the carb on and did you adj your air fuel mix im wondering if you have something out of adj because it runs ok untill you mash on it and you might be over fueling it.....

 

[Bronc76]

you may also want to check for vacuum leaks at carb or intake manifold

 

[kingbronco]

I put the intake and carb on about 3 weeks ago and have been fixing problems since. Edelbrock says the air fuel screws only affect idol so i haven't touched them since i put it on. It does have 110 primary jets and 107 secondary jets which to me sound a little on the large size.

 

[white night]

I put the intake and carb on about 3 weeks ago and have been fixing problems since. Edelbrock says the air fuel screws only affect idol so i haven't touched them since i put it on. It does have 110 primary jets and 107 secondary jets which to me sound a little on the large size.

i think that you are aver fueling the cylinders and that is your problem if you dont know how to adj your carb i would take it and have it tuned.

 

[Yardape]

I put the intake and carb on about 3 weeks ago and have been fixing problems since. Edelbrock says the air fuel screws only affect idol so i haven't touched them since i put it on. It does have 110 primary jets and 107 secondary jets which to me sound a little on the large size.

Edelbrock is very user friendly, unless you got a bad one they are supposed to be tuned and ready right out of the box.

 

[Yardape]

Maybe you could add what size engine you have, any other mods

 

[kingbronco]

its a 460 small cam cant really even tell it has one except at idol edelbrock carb and intake and a Jacobs electronic ignition that i hate and wish i could take out it sucks..

 

[Yardape]

Does your jacobs box have a timing control in it?

 

[kingbronco]

No or not that i can see im used to MSD boxes so they might have hid it.

 

[kingbronco]

Problem fixed it was just a simple timing problem.