2004 ranger

[myold96]

not sure where to put this but a friend of mine has a 2004 ranger with a 4.0 engine that has a random misfire that causes the engine to idle rough and lose power we have changed the spark plugs wires and coil packs and module,we have added fuel system cleaner and nothing helped thinking of changing the injectors next but that is more invasive and expensive and he is broke i think they changed the computer also,i think he is just throwing money at it hoping to fix it. i think he has bad injectors or bad fuel pump or regulator but they don't want me to work on then they would have to pay me,maybe if they heard it from the people on this forum they would listen.

 

[Mark_88]

Best place would be the 4.0 forum below the 4 banger...they are all very similar theoretically and practically in some cases...but there may be issues with one that are not necessarily the same as another...

But, anyway...pulling the codes might tell him more than throwing parts and money at it...get a code reader and start there...might be specific or vague though.

 

[tomw]

I would add two things. Fuel pressure and delivery volume for one, and check the upper and lower intake manifold gaskets for two. The gaskets will show their problems when the engine is cold in most cases.
tom