Originally Posted by Scooterz
Thanks again Ken & DD. I am not used to Mopar stuff at all. Just a different bird... the starter is weird sounding, the valve train has a different sound (not bad) just different. You guys know a lifter tap or small exhaust leak is like fingernails on a chalkboard to a gear head.... but it does go away. Seems like a good motor.
It has 9: 1 pistons & does not like regular gas!! Pings under load in mid range. Put 92 oct in it & it is gone. With 9: 1 pistons, I wouldn't think the lower octane would matter?? WTH.
Sounds like a timing issue here. Is the mechanical advance hanging or perhaps opening up too soon? Might be worth looking at because this isn't (or shouldn't be) a computer operated engine.
Or, the vacuum advance isn't returning soon enough. Could be something as stupid as a small vacuum leak in the hose or diaphram.