[MaineHandyman]

ive tried timing my truck once again and the exuast sounds like its misfiring, if you listen to the exuast when the engine is running it sounds erratic, like its misfiring, what can cause that? its a 78' 350 runs rough, any thoughts?

 

[BogiesAnnex1]

ive tried timing my truck once again and the exuast sounds like its misfiring, if you listen to the exuast when the engine is running it sounds erratic, like its misfiring, what can cause that? its a 78' 350 runs rough, any thoughts?

Being a 78 SBC, the first place I'd suspect is a wiped cam lobe. Check for a wet to oily plug, if you find that, pull the rocker cover above that cylinder and observe the valve stem motion.

Bogie

 

[MaineHandyman]

sbc

i actually checked all plugs they are perfect, i did find a leak in the intake manifold right under the carb there was a hole that a long time ago i had to make a plate to cover it because it use to be choke spring i believe, but could that cause rough driving and high feul consumption?

 

[eloc431962]

Check for vacuum leaks. Bad plug or plug wire. What kind of ignition do you have? Cole