Sudden Hard Miss, Rough Idle

[dkmunns]

I Have An 2002 W/7.3, Ran Perfect, I Stopped And It Idled For About 5 Min. Started To Drive Off And It Surged, The Light Came On And Its Missing Bad. No Codes Show Up? Could This Be The Infamous Harness Connection At The Valve Covers ?

[djsdiesel]

If your check engine light is on, there should be codes. But it definately sounds like under valve cover wiring harness came disconnected.

[SCUFFY828]

sounds like harness conection to me but its funny you dont have codes if scanner wil run injector electrical test f passes becaue you dont have any codes believe i would check fuel pressure next, no codes to me always leads me towards fuel issues if everything else checks out

[99dieselsmoke]

check your fuel/water separator. take the fuel filter out and see if theres any build up in the bottom. take separator out and clean it. should clear up the rough idle and miss.

[Marty]

Where did you get it scanned?

[bighunter]

Im having the same problems. I start my truck and it begins to run perfect for the first 1-2 seconds, then it it runs really rough. I replaced the engine wiring harness and no change. fuel filter has fuel in it and a new filter(3000 miles) this started when I was just about to run out of fuel. What do you guys think? I have had this problem for about 6 weeks now. no power just nasty rough idle. I cant drive it this way and Im tired of driving my wifes f150.