7.3 running very rough???

[dieselbop]

can someone help me with my situation? I have a 1999 7.3 that is running very rough. Feels like it is misfiring. On the freeway it runs fine until you have to accelerate up a hill than it runs very rough and smooths out. What could this be?

[SCUFFY828]

check oil levl and make sure its been changed recently ,or possibly have short harness coming loose under valve cover ,really need to get codes pulled ,you could possibly even have low fuel pressure , if only does it under load

[dieselbop]

i just changed the oil last week. I have a couple of codes but those codes are due to the 18k dfuser that is in the truck and the ebv valve being unplugged.

[SCUFFY828]

i believe i would run a fuel pressure test , if thats good , if you can get your hands on a scanner that shows data , i would monitor icp press, ipr %, rpm signal ,and boost pressure ,just to see if there reading correctly , if you can also run injector buzz test just to make sure all eletrical is ok, alot of times no codes leads me toward fuel press

[dieselbop]

thanks for the help. I will try a fuel pressure test. I don't have access to a scanner. I am reading the codes from my superchip. What should fuel pressure be?

[SCUFFY828]

50-60 lbs with key on doesnt have to be running

[dieselbop]

did you mean 50-60 p.s.i? I'll test it this week.

[SCUFFY828]

yes 50 -60 psi with key on engine doesnt have t be running has electric pump

[guzzle]

Like scott, I would agree that without having codes pulled, I would check the UVC harnesses for chaffing or hot spots. Some of the 99's had the injector wires that were routed too close to the rockers and wound intermittently short whenever the lifter touched it. The UVC connectors are also infamous for loosening up and having poor connections. Ford and International have new clips that will hold the connector together but some have reported that the clip is too thick and will split the plastic on the UVC and needs to be modified before installing.

[dieselbop]

I took it to the shop today and just for the heck of it I checked the oil leve. The oil was way over full and smelled badly of diesel fuel. I changed the oil last week and checked the level. I think I have an injector problem. Is there anyway of checking the injectors so I can isolate which one it is? Resistance check?