Hey guys, I just purchased a 83 fj60. it runs great when the black tach wire at the igniter is unhooked. When this wire is hooked up the engine idles smooth as it should but as soon as the RPMS hit 1800 or higher on the tach it surges like the ignition is being turned off for a second, its worse when its being driven. Is this signs of a bad igniter? or bad tach?