grabbem88

that's what i was thinking,butif it's lean then 10mpg is awsome![&:]....

dizzy could be shot?...timing chain could be stretched?

Evil_F

My first guess would be dizzy. I think the timing chain would cause a little different problems. Because your valve timing would be off, it wouldnt really buck like that.

grabbem88

since i didn't do the float<this is why asked what would be the most likely symptom

grabbem88

so when i played with...i made certain ranges of engine load to be masked,but fail somewhere else?

Evil_F

If your floats are low, they can drain quickly causing your car to loose fuel at wide open throttle. But you would only go lean when on the peddle. Not randomly, or only in 4th gear. If floats are to high your car may run rich, but it wouldnt just be in 4th gear.

grabbem88

i've got it to do the backfire in all gears...just more pronounced in 4th then 3rd

Evil_F

Backfiring out of the carb or out of the tail pipe.?

grabbem88

CARB ONLY....never out back

Evil_F

Floats may be set to high.

grabbem88

i can have the truck sitting still,and blip the gas a few times,and i can get it to backfire through the carb