Hi have 93 blazer K1500 has about 226k it has a rough idle and acts like it wants to stall out if I put it in gear with out it running for like 5 mins or so then it'll really want to stall out unless I get on the gas.. Hears a list of stuff I have replaced not cause I thought its what it needed but some were codes some I knew needed to be replaced. Knock sensor, iac valve, fuel relay, icm, dist cap and rotor, plugs and wires, therm sensor, thermostat, therm switch, fuel filter, fuel pump. Also my temp gauge doesn't move at all only time is when I first start it it'll go up and back down and won't move same with speedometer. When the truck is idling the rpm will be between 400 and 1200 rpm but will fluctuate constantly till the engine smooths out timing was set correctly to 0 also.. I'm lost with options please help me.