86base

iTrader: (3)

I got this 91 fc na thats knocking above 3500 rpm any thoughts

patman

iTrader: (3)

secondary injectors.

DO NOT DRIVE until its fixed, you will blow your engine.

pat

sleejay

what exactly does knocking feel like

86base

iTrader: (3)

do you know what it might be ?

patman

iTrader: (3)

knocking on a NA is caused by two things:

too much timing advance
not enough fuel

since it doesnt knock at low rpm, that probably means that your timing is ok
secondary injectors come on at 3500 rpm. so does your knocking.
which means that your secondary injectors are working poorly or not at all, causing a lean condition, and knocking.

pat

86base

iTrader: (3)

thanks Ill check it out