93 Ramcharger help

I have only had this truck 3 weeks and it was in terrible disrepair when I got it. The cap was broken and wires were melted to the manifold. I did the cap/rototor/wires and plugs. run good. I noticed the coil was also cracked, so I replaced it too. I don't know about the fuel pump. There is a reciept showing it was repaced, but the gauge is WAY off, so I will be putting one in there soon. The oil was so dirty and thick, after having 600 miles on it it needs to be changed again soon, it's dirty again. I did hoses, t-stat, flush radiator, new suspension components etc... The truck really is running good, except for the sputter, miss and backfire every 2-300 miles.
I noticed that after it does it, the next day it has no more problems. I kind think it may be fuel related or the pump is sucking something into the pickup and after it shuts down, releases it from the tube and runs good again.