Was running good and starting good happend all of sudden. I dont drive it much maybe 1 time every 2 weeks to work and during hunting season. After I do get started it smokes black with tach bouncing to 5 grand then smoothes out, took it out and got on it and is sluggish and poping through intake. Could it be bad gas? Dont have a code reader, check engine light not on.
The jumping RPM's could be caused by your IAC (Idle Air Control). It's around your throttle body and you can take it off and spray carb cleaner in there if it's dirty and itll loosen up all the crap inside. People say it does and doesnt work, some people have had trouble with cleaning the IAC and say they ruined the IAC. If you'd rather buy a new IAC, I believe they cost around $75-100, if I remember correctly.
You can also try a product called Sea Foam. Dont know if you ever heard of it but it cleans the carbon build up. Im sure if you research Sea Foam you'll find plenty of reviews about it. You use it through your brake booster line and suck it up and let it sit for 15-30mins, then turn you truck on and it should smoke like crazy. But research it and you'll find more exact details on how to use it.