03 6.0 Problem

[engstrom97]

Background: 03 6.0 Magnaflow cat back exhaust, zoo-dad mod and the rest is bone stock. 45K miles, I use Opti-lube fuel additive. Rotella T 15-40.

Man yesterday I jumped in the truck to go to lunch, drove about 10 miles to get to the place we were going. Pull into a parking spot and the truck is idling a bit rougher than usual, this happened a month ago and 2 injectors were bad. Shut the truck off went in and ate, came back out fired up the truck and it runs great. To investigate a little more went and got onto the interstate, got on it and it runs strong. All seemed fine till I got into the work parking lot, it was running even rougher. Well needless to say after work I came out fired the truck up to drive home, was still a little rough got two lights from the house and the truck was running so rough I didn't think it was going to keep running, then it would barelly move when the light turned green. After it gets the RPM's up a bit it goes OK but initial take off is almost non existant!! Any ideas, I am thinking it is some more injectors but why would It get worse as it warms up??

[landofconfusion]

I had a similar problem with my 03 6.0 man. when i would stop it would fluctuate idle RPMs so much u would have thought a blonde was trying to make up her mind about shoes. Any who, when i accelerated it was really sluggish. I took it down to the dealership and underwarrenty got it reflashed for free. They have an update for our 03's and it makes it run alot smoother. And without any performacnce engine mods you can feel the extra power and acceleration. I have no idea if this has anything to do with the price of tea in china, but my dad has a f250 gasser and he had a fuse go bad in the box, and i dont remember which one but it made it have the exact same syptoms as yours. FYI
good luck buddy

[Clay Henry]

Doesn't sound like injectors but i could be wrong...someone smarter than me will address this i'm sure.

[SCUFFY828]

two things come to mind , low fuel pressure like pump trying to fail , which could have caused the other injectors to fail, or a wiring issue being its an 03 , the ficm harness may be rubbing the side of the engine

[engstrom97]

I just replaced the fuel filters both top and bottom, and drained the water/fuel seperator. It goes in on Thursday to see what is going on.

[Clay Henry]

Originally Posted by engstrom97

I just replaced the fuel filters both top and bottom, and drained the water/fuel seperator. It goes in on Thursday to see what is going on.

It'll take 5 minutes for them to check fuel pressure. That very well could be it.

[engstrom97]

Well I just got a call from my service guy. Said it was another bad injector. He said he needs to change the oil cause that can be causing the problem (Rotella T with 1700 miles on it). He asked if he could keep it and test it tomorrow so I said sure, he also said that he was going to make Ford pay the deductable which is nice.

Do you guys think I should call him back and have them do a fuel pressure test on it??