MOTOR 86 B2000

so basicly tonight i was drivin down the freeway at a cool 60mph, in 5th, and all of a sudden a "ting ting"came up and i noticed a MAJOR LOSS in HP.so i pulled over... normaly it idals at 1200 rpmsno it doesn't wanna go above 4 or 500 rpms,its definitly sumthing wrong with the motor...i dont know what,but any help?? its seriously messed upbut yet, it didnt smoke or anything...i just hurd a ting noise then, well that's it.please help me asaptell me new motor, head, anythinglemme knothanks

ting ting no power no revs... a valve could have broken pull off the valve cover and take a look.

but just going down the freeway??
it just gives out... hmm...
ya it seems like i have NO hp at all
and like i said it doesnt wanna run... but yet it still idals at 500 lol