hi my 1990 camaro 3.1 has been backfiring everyonce and a while idleing really rough(car vibrates) misfiring when its warmed up,it doesnt di,and has lots of valve chatter when i accel quickly.theres no loss in power just makes for a really jerky ridei cant seem to find whats wrong with it.

has new ignition coil,new plugs and wires,new cap and
rotor,cleaned the egr,mechanic said timing is spot on,new o2 sensor,no exhaust leaks,cleaned iac motor

i need some help quick this is my daily driver
thank you

 

If its backfiring it sounds like you should check your timing.

 

mechanic said timing was good, but ima take it to a diferent shop(prob thinks ima take it to him if chain snaps lol)

 

bump