2005 Ford Freestar check engine light

[boatfixer]

Check engine light came on, runs rough. Mrs boatfixer takes it to a shop that has done work for me before and I trust them. Tech took a quick scan and said #2 was mis-firing. Said pretty sure it's an injector, probably not a coil. Question, Can't the fancy schmancy scanner tell the difference between an ignition and fuel problem? She is taking it back in tomorrow for a better look. What can I expect to pay for cleaning injectors?

[Jeremy airjer W]

No!

The "fancy schmancy scanner" cannot tell you anything more than the cylinder that the misfire is on (P0302 - #2 misfire). Its up to the tech to put his/her brain to work to rule out all the possibilities except the one that is causing the problem. These possibilities can be, a vacuum leak, burnt valve, burnt piston, any other source of poor compression, ad spark plug, bad valve seals (oil foiling of the plug), week injector, bad coil, wiring between the PCM and affected coil/injector, PCM, worn cam, bad lifter, and the list goes on and on. It would be nice if there was a "fancy schmancy scanner" though!

If this is the 3.0 DOHC 24 valve engine it has coil over coils. One coil per cylinder. In my experience I have replaced way more coils than injectors on this engine. Unfortunately I think that the # 2 coil is under the plenum so it can not easily be moved to another cylinder to see if the misfire follows the coil or not. Typically you can use a spark tester and watch the spark fail as you crank it over (the other coils need to be disconnected so the vehicle will not start with the plenum off).

[boatfixer]

Oops! I forgot to add it comes and goes. Not there all the time. And it's a 3.9l. My bad!

[Scott K]

Airjer is correct, I too would guess coil pack over injector. You can hook up tools te determine if it is a coil causing the miss, or an injector. But it is easier to swap part to a different cyl. and see if the miss moves to the other cyl

[Shack]

I would also say C.O.P...

I would think intake leaking, before a failed inj...

[boatfixer]

Whew!!! Dirty injectors. Runs great and Mrs. B is happy again.

[Jeremy airjer W]

WOW that hurts!! I guess we all get a swing and a miss every once and a while. Glad to hear it was a simple and probably relatively inexpensive to repair!