94f450
Registered User
A friend of mine has a 93 NA 7.3 that he has been trying to chase down problems with. After a 3 hr trip in the truck he came home and let it idle for awhile. The truck started to run really rough and has progressively got worse. He can make the truck do it by holding the throttle around 2000 rpm and when he lets off it will idle rough. Almost like its starving for fuel? We found it had 2 psi at the filter head so he changed out the lift pump with a new mechanical unit... still had 2 psi so he went with an electric pump and now has 5psi. He though maybe it was an air leak so he replaced the fuel lines all the way back to the tank, replaced both tanks, and the selector valve between tanks! None of this has solved the issue!!! Has DPS injectors and injection pump that are less than a year old with maybe 2000 miles on them. Return lines and caps are new. What do you guys think!?