Hello To All. I Have A Problem With My F250 5.4l V8 Manual. Starting About Two Months Ago I Had A Problem With The Truck Not Idling Correctly Or No Idle At All. So Figured To Change The FUELFILTER And Pvc And Run Some Fuel Treatment Through It. After That It Fix The Problem For A Little While And Then It Returned. So I Left It As Is And About 2 Weeks Ago The Motor Started To Hesitate In Low Rpm While On Load. Then The Cel Fliped Showing Codes That Coil 6 & 7 Misfire. So I Change The Plugs And Put In New Coils. What Da Yea Know Problem Still There. I Had Ford Run The Computer Check-ect And No Problems Showed. ($95 Test) Well Now I Am Pulling My Hair And Getting Know Where. Anyone Has Answers To This Or Might Know Where To Start Please Reply.

Thank You,
G. S.

 

The idle problem is probably the IAC. Pretty common. Not sure on the miss though. There is no water or anti-freeze getting into the spark plug pockets is there?

 

No Water Or Anti-freeze But Have A Lot Of Black Sort Soot At The Tail Pipes.

 

that almost sounds like possibly a mass air flow sensor....... if that is acting up, it will give it a bad idle, and could tell the engine bad fuel pulses causing a real rich condition. that could give you a black sooty exhaust. does it smoke and smell real bad? seems that it should throw a code though......

 

Mattd17 I Am Going To Check Out The Maf Sensor And Also I Had A 0307&0306 Code Show Misfire On The Cops. I Went Ahead Replaced Those And No Gain. Yes I Have A Lot Of Black Soot At The Tail Pipes. Talking To My Friend And Others This Black S. Is The Cause Of Rich Comditions (raw Gas + Backfires). The Good Ol Emissions.

 

Could the soot have fouled the plugs while you were tring to figure out what was up with it??

 

it is possible to have fouled the plugs. it wouldnt be a bad idea to pull them, and clean them at least. also, while they are out, i would re-check the gap. if they are fouled, it would probably be from the injectors dumping too much fuel..... which could be from a faulty MAF. be real careful cleaning the MAF. be sure to let it dry completely before trying to run the engine, or you could short the heating element. good luck !!!

 

A dirty MAF will actually cause a lean condition, not a rich condition. When dirty, it will not sense as much airflow and not add enough fuel.

 

I DID CHANGE THE PLUGS WITH THE BOCSH PLAT. AND NO GAIN. FROM READING ABOUT THE BOCSHS I AM GOING BACK TO THE MOTORCRAFTS.

 

Hey guys the hair pulling, frustrated 2-month project accomplished. Pulled out MAF cleaned with Crs Air-Intake Cleaner {let it dry before install}. Pulled off throttle body, took apart and cleaned with Crs {all spacers, IAC in and out). Cleaned all breather lines {PVC line and the other ventilation line). Sprayed down into manifold w/ one can then pulled out ignition fuse turned over motor to let cleaner spread out and do its job. Also pulled out the (2rd) bosh plugs and replaced w/ (3rd) auto lite platinum {check gap .054). Then checked resistance on the coil {between .05-1.5ohms). Checked resistance on injectors {13.8-15.2ohms). Reinstalled . Started up took for drive and the power better then ever back. This was done on 5.4L V8. Thanks to all very much and hope this will help others.

George

 

Glad you got it figured out

 

Way to go!!