Causes of engine running rough

[Premierexplorer]

My 92 explorer runs rough at idle. I have a new fuel pressure regulator, iac, fuel filter, spark plugs and wires also cleaned maf and injectors yet i still have a rough idle. Anyone have ideas?

 

[monkeydude3]

How did you clean the injectors? How is your air filter and throttle body? I would definitely reccomend taking off your IAC (idle air control) valve and clean that... cleared up some of my troubles. keep me posted I've got a 1994 XL 4.0L OHV and my dad has a 97 aerostar... 4.0L OHV

 

[MrShorty]

Cleaning the IAC would be a good first step.
If that doesn't do it, then I would pull codes from the computer. Some faults don't trigger the check engine light to come on. Even if you get all pass codes, that can be worth knowing.
A new fuel pressure regulator doesn't mean that the fuel pressure is correct. I would verify the fuel pressure.

 

[Premierexplorer]

the iac is about 3 months old so i dont think it will need to be cleaned. I will try pulling codes to start with.

 

[TPLYNCH]

Check for vacuum leaks. Make sure all caps are on the unused lines on the "octopus" tight and that none of the lines have cracks in them.