02 f150 5.4 code reads misfire on 4@6 changed plugs did not fix,whats my next step?

 

Any past problems ? You change the plugs recently ? All of the sudden, you have TWO cylinders not hitting ? What did you do lol.

Change fuel filter and check pump pressure's, IF this occurred out of the blue.

Usually you won't get two like that on a CoilOnPlug ignition unless it either got wet or the pump, regulator is going bad. Could be the relay or maybe you messed with the harness ? A chaffed a harness wire on top of your AC Accumulator can create ignition havoc = short + mag field disturbance.

Need more info, spill it - woe, not like that.. What were your exact codes, do you recall by chance ?

 

get back to basics, Fuel-Compression-Spark. Are the plugs firing??? Are the plugs wet??? fuel press??? Injector plugged?? Compresssion??? Leak down test????

 

Uhm, who's getting away from basics here

 

don't get any more basic than that. start throwing parts at a problem with out testing is not smart. not too many guys with 3v's throw a set of plugs in to cure a misfire without determining the cause first. eg. be pretty dumb to start buying coil packs before checking to see if you got fuel.
Like I said check spark, fuel, then if needed compression and leak down.

 

Did someone say to throw parts at it

Man, your different ?

 

I think telling a guy "Change the filter" before doing and diagnosing would qualify as throwing parts at it. Not sure how fuel press would cause a miss on 2 cylinders, and no fuel trim codes???
A word of advice, never let any one tell you witch parts to change, only witch parts to test, you'll save a lot of $$$

 

Next thing your going to say is your a tech @ Ford. - I hope not.

I said that so that IF his filter was replaced, he will post that. If not,- to accurately preform a fuel system check, the filter should be changed. This is a maintenance Item

You saying "your not sure" - you sure are correct about that.

 

Is changing you oil and filter" throwing parts at it" to? Jbrew is suggesting the guy do a simple inexpensive maintenance item that CAN cause injector to quit working causing a missfire..
Did you register just to see if you could stir the pot?

 

Guessing and throwing parts just don't cut it in the real world.
My sugestion: if you wanna guess, go buy a lotto ticket, if you want to find the problem do some diagnosing. I don't have a crystal ball, so I can't tell you from my computer exactly what it will take to fix the problem, I can only sugest a SMART course of action.

What I'm trying to say is, in the half hour it takes to "guess" at the fuel filter you could pull a plug and at the very least eliminate the ENTIRE fuel system or the ENTIRE ignition system, and thats money in your pocket. If that kind of diaganosing was used in the first place he would have the coin he shelled out for plugs in his pocket, ready to pay to fix the REAL problem.

 

Subtle approach:

Well, you went from being different to augering out a hole in your marble bag.

Lets just see bamaford02 has to say, there wasn't much to go on. -Reason for questioning in post #2 of this thread.

I can't help with your problems.

 

I love it here, makes being laid off, all that much better!