Hi everyone i own a 2003 3L. ranger and the engine is not stable at idle and even in gear.When i release the clutch and i fuel it a bit the engine is trying to drive the rev like a bungee but it is better when it s warmer. The spark plug and wires are new,the fuel filter and air filter too.Please can anybody help me with it.

 

Did this problem exist before you replaced the indicated parts? What brand of plugs and wires did you install? Ranger engines seem partial to Motorcraft plugs and wires.

 

Do you have a CEL lit???? If so scan the computer & post All trouble code Numbers found, as they can offer up good trouble shooting clues.

The IAC is responsible for maintaining engine idle speed, so it sorta sounds like it should be on your suspect list & it's a common problem part in idle woes. Vacuum leaks too & this would include the PCV valve.

You could try removing & cleaning the IAC with a plastic safe spray cleaner to see if it'll help.
Cleaning may not last, it didn't for me, but was a good trouble shooting step.

More thoughts for consideration. Let us know how it goes.

Edit: BTW, welcome to FTE.