i have a 93 s-10 4.3. it ran fine until it sat for about 4 months. got it running again and it is popping through the exhaust. it doesnt do it on every compression stroke just every now a then. mainly at idle. if i remove #5 plug wire it quits. i removed plug and it looks fine. removed valve cover and checked for broke valve spring. nothing found. checked compression. it seems to be a little low but not too bad. any advice would be helpful and appreciated.

Welcome to AF.
What are the compression readings dry and wet?
How are the cam lobes?
Are all valves opening good?

on the first stroke it came up to about 75 and then it built up to 160 or so. that was dry. thats all i did because i was just trying to get a rough idea if a valve was bent. the valves seem to be opening fine. im not sure about the cam. all i have off the engine is the valve covers

You might try putting another spark plug wire on #5. Be careful around the knock sensor next to that plug.