Car acts like it is out of time ocassionaly

[rede4christ]

My 87gn runs great starts up every time in the driveway when cold but sometimes after it had been started a few times it will crank like it is way out of time and backfire so hard a few times I thought for sure it had to blow the mufflers off.after it sits for a while probably45 mins or
So it will fire right up like nothings wrong.