my 86fc is really messed up, for some reason it only starts up when its really cold outside, or it hasnt been touched for a while, and for some reason when i stop the car, and about to go into reverse, it dies, could the first problem be the plugs or sumtin i dont know

 

are your rpms jumping up and down when your just idling?

 

no i think they're stable most of the time, but when i change gear from park to D or to R or sumtin they jump up to like 5000 but go down later when i start moving