86 rx7 misfiring
 

for sum reason when i dump the clutch to burn out in 1st it misfires but when i do it in reverse it doesnt. also when the car is cold i dont have a problem but when its warmed up sum times when i stomp on the gas it misfires. i got new plugs and wires in any1 kno what the problem could be? also when i start the car when cold the idle jump constantly from 1000-2000. help me plz!!!!