I have a 1991 chevy k1500 We just put new motor in it and it has been broke in But we still have grayish black smoke coming from exhaust and it only comes from it when you give it alot of gas and you can smell gas fumes from just standing by it Did a fuel pressure check and its at 13 Driving it and at idle no smoke just when you get in to it Any help would be great <!--POLLS--><!--FILES--><!--SIGNATURE-->

 

Might be float in carb is too high.

 

Check the vac lines to the map sensor. Also check the map sensor connector they were prone to failure. Wiggle the connector while its running does it change the way it runs. You need a scan tool that you can see the data.

 

it's running too rich, O2 may be reading lean condition and adding fuel. mine was doing it for a while after i straight piped it.