Thanks for any suggestions - First time Ford/Ranger owner, 2002 XLT, 2WD, 3.0, 165K miles. I have owned it now for 1 tank of gas and it starts running rough, then check engine light comes on. I have the codes checked 3 times: misfire on 4, 5 and 6 cylinders, OS, MAF, too rich/lean... and I don't trust any of them. So... I clean the MAF, IAC, and seafoam - lots of carbon everywhere. Now when I am idling I can't get the RPM's over 3000. I am done for the day, will try more tomorrow - any suggestions on what to try next - the one shop wanted to give me a tune-up, but the wires look pretty new, and I am thinking why would you change the wires and not the plugs too. Any suggestions would be appreciated.

 

If you have an automatic and have the gear in neutral, the computer won't let you rev over 3000-3500 or something like that; some kind of safety device.

 

Thanks, at least one item down - just got back from a ride -runs a lot better, but CEL came back on

 

Pull the spark plugs and have a look at them. This will give you a pretty good idea on how the engine is burning fuel. Compression check, vacuum check, replace the plugs, clean the throttle body, check the PVC valve, EGR Valve, and clear the codes. You might have a problem with the cam snycro. I'm no computer guru by a long shot but Misfire is a symptom.

don't listen to me though, we still have not figured out why my engine runs rough and idles too high.

Good Luck !!

 

Thanks for the directions - I'll start reading now so as to learn how to do the above

 

i havent done any work on the 3.0 but my buddy has a v8 and we changed his spark plug wires, head gasket seal, and spark plug. that fixed his problem... it was the same as yours...
my automotive teacher said that if you plug wires are touch any kind of metal it will cause an electrical short... so the power never gets to the plug... he also said it depends on how thick the installation is on the wire

 

spray the wires with water and watch for sparks. diagnostics will save you hundreds.

 

love the cheap diagnostics - thanks for the ideas - cleaning the throttle body tonight

 

Clean the ground connections from the battery to the engine ,frame, and firewall.
Some have found a bad ground to cause mis-fires.

 

thanks to all for your help - still working on it