Hi,

I have a 71 Mustang & need some help.
4 of the 8 spark plugs are not working. (they are all new) I've swopped them out & they all
work fine so its not the plugs. replaced the wires,coil,distributor cap, roter
arm - all working fine.
checked compression in the engine (max is 150 - low is 125)
checked for leaks in the intake manafold-didnt notice anything.
Dont know what else to check- i'm new to all this so all help is greatly
appreicated

Thanks!