ok, i give up help please

[J8346]

i have a 85 2.0 standard 1barrel carb,

i have replaced,,,

cap, rotor, plugs, ignition module, voltage regulator, fuel pump,
installed carb kit,, new muffler, new vacume lines,new distributor

and, i still have the same problem

truck pops back,,, like backfires, only on the exaust, and only after revving up and between gear shifts..

no power steering, no power brakes..

any ideas

 

[4.0B2]

is everything you've replaced been stock parts? is it all stock?

 

[J8346]

EVERYTHING STOCK PARTS,, engine stock no mods at all

 

[MikeInID]

Just a wild shot in the dark, have you verified timing?

 

[Rogue_Wulff]

Popping out the exhaust? Most likely, you have an exhaust leak.

 

[tomw]

If your truck has an air pump, it is supposed to have a 'gulp valve' that stops feeding air to the exhaust when you take your foot off the gas pedal. If the valve fails, you can get backfire out the exhaust when you suddenly close the throttle.
If you don't have an air pump, you may have too much fuel getting sucked in through the idle circuit, causing the same noise. Make sure 1)your idle mix is as lean as possible without miss and 2)your idle speed is properly adjusted. A high idle speed can allow more fuel/air into the exhaust under closed throttle conditions leading to backfire.
tom

 

[J8346]

Damn air pump was the the issue,, removed the belt and solved the problem...

Thanks all for the help...