6.0 Powerstroke loses power, runs rough. Then runs great.??? What!!
 

Very confused. A year and a half ago I was driving my 03 6.0 down the road and it started missing and wouldn't think about accelerating. I shut it off and it wouldn't start. I towed it home. After I let it sit for a few days it would fire right back up but fall on its face in about 10 minutes of idling. So I parked it and haven't touched it since I haven't had the money to fix it. So the other day I put fresh batteries in it and turned the key and it fired right up. Ran for over an hour without a problem. Drove it about 70 miles, changed the oil and fuel filters and kept driving. NO PROBLEMS!!! I thought it was just bad batteries til today when it done it again. It started missing in the driveway then it cleared up. Drove it all day and no problems since. What is the deal? No codes or smoke. I wont have access to a scanner til Tuesday. Truck is all stock. I appreciate any help yall.

Eric

Bad connection on ground?? Or wiring? Computer or ficm wiring? Check your fuel and oil pressures. . Hope u can get info from scanner. .

I had it running earlier and it cut out. I grabbed the wiring at the middle plug of the ficm and it straightened out and when I pulled it back it went back to sputtering. Now it wont fire. Im gonna pull it apart tomorrow and see if I can find a short. I hope it aint the FICM. I had it rebuilt by Swamps 2 years ago and the wiring harness was replaced at the same time.

Is your clip broken? Common for them to get brittle

Naw it ain't broke it feels like its in there good. Will know more when I tear it apart. I'm hoping the plug in the fixing itself ain't bad