Ihave a Dodge ram 1500 1998 with a 3.9L and it idles rough like a miss, i changed the plugs, wires, dist. cap and button,I.A.C., fuel injector flushed, throttle body removed and cleaned,still didn't change, had themotor mounts check there good, all the pulleys are good, and fan turns smooth. and checked for vacuum leak didn't find any, hears what it does, itidles rough but as soon as you give it gas it smooths out and drives just fine. it doesn't stall or back fire, starts up just fine, and there is no check engine light on and i checked for codes, nothing. even tried gas treatment several times, still the same, and i did a compression check it shows to be good. please help with any ideas I'm stuck.

 

moe in wichita ks
i to have a v 6 that idles rough but mines not as bad as yours. i did hear that on some engines if something is loose and rattling it cause the knock sencer thinks the engine is detoneating and turns the timming down. but i dont know which engines have that system.