I have recently purchased a 2006 f150 with the 5.4L V3 motor....here is what has happened since my purchase... bear with me my nerves are shot! driving home on the interstate after i bought the truck i was going into a curve and tried to accelerate ...the truck stumbled and acted as oif it was out of gas or missing or something...the check engine light comes on blinking and the truck acts as if it has no power...I pull over and turn the ignition off... i wait about 3-5 minutes and start it back up and drive home..at that point it was driving rough...well i check these forums and see that im not the Lone Ranger...so heres what ive replaced ...all 8 spark plugs ...4 ignition coils ...2 conectors to the ignition coils ....the fuel punp module...and a more advanced obd2 scan tool than i had before...the zurich zr11 from harbor freight.i was getting a # 8 cylinder misfire so i replaced the coil eith one from the #3 cylinder then i got a # 3 cylinder misfire ...i was getting hopeful at this point...replaced the coil on 3 and now I get a p0300 random misfirs detected ....im checking things now that are of no concern to the current issues because im out of ideas or next moves...please give me some direction here ..I thank you in advance!

 

did you use motorcraft sp546 plugs? What led you to replace the 4 coil? Still sounds like a secondary ignition misfire.

 

yes i did use the sp546 plugs and i used the 4 coil to switch out with the 8 coil to see if it was a bad coil on cylinder 8.

 

What brand coil's ? I would replace all 8... that will give you all new boots and springs. how many miles on the motor ?

 

they were Duralast from autzone..

 

sorry the truck has 265,000+ miles ...and am I understanding you when you say to buy all 8 new coils that it could be the issue? Kinda running low on $ and I don't want to spend it if it is not absolutely necessary..

 

At those miles you should have replaced all the boots. No need to change all coils clean each cop terminals real good they corrode, use a small amount of dielectric grease on each end of boot. Do a hospital grade clean plug install . Torque wrench all plugs 25 to 28 foot pounds . look at mode six and see what cly are building raw computer counts toward a misfire. You are in the zone of needing new injectors,you can pull the rails clean and test them see you tube ..Its not all spark problems ,fuel and air are also in question .you should clean your throttle body while your at it .

 

okay awesome now we're getting somewhere! i will replace the rest of the coils..only four or five left anyways..I've cleaned the throttle body and maf sensor ...and will pull the fuel rails and test them tomorrow...UPDATE!!....another code i will include pics of the diagnostic ...code p1184 engine oil temperature sensor out of test range ..this came up when trying to run the Ford oem enhanced KOER...I checked the plug unpluged it cleaned it up and put it back in the sensor...i will change it tomorrow...see pics...thank you guys! will keep you posted on results...

 

I would leave it alone for now.. the P1000 is not effecting anything, that just tells you , you have not completed a full drive cycle. you must have disconnected the battery at some point. A flashing CEL is a classic sign of a misfire condition. Not sure when plugs were done last. Boots and springs will cause a misfire too.