I have a 2006 ranger xlt 4x4 with a very rough idle in park and drive. I've replaced the fuel pump, filter, and injectors as well as plugs, wires, and coil pack. Currently has 175xxx miles and regularly maintained. So I'm lost with this issue. Someone please help me out with this head scratcher. NO check engine light throughout issue either.

 

clean the mass air flow sensor WITH MASS AIR FLOW SENSOR CLEANER (nothing else!!), change air filter, clean throttle body and air intake with throttle body cleaner. Run a can of seafoam through the intake. Change oil. All of this stuff can be done for less than 40 bucks and take maybe 90 minutes of your time.

Does it do it when cold started, or after it warms up?

 

I cleaned everything when I did the injectors this past saturday. Oil was done last weekend. Havent done theseafoam yet. Idles rough on startup then gets a little better as it warms up but still rough. RPM stays at about 750 though.

 

No idea then