hello I have a 96 super duty regular cab dump truck. it has a 7.3 5 speed with 167,000 miles on it. I am not the original owner but I do know it was a Dept of Highways truck originally. I have been having trouble with it recently. It has been missing and sputtering in the higher rpm's when taking off and changing gears. it also seems to do this when pulling hills even when the truck is empty. it has gotten so bad that I have to downshift to 4th gear on hills that I used to go up in 5th with no problem. I live in wv so we have some pretty steep mountains to climb. it seems to idle rough when parked (the truck rocks back and forth at idle, not smooth like it should be).. the truck puts out white smoke on start up and when accelerating and shifting it blows white smoke but when I am in 5th gear on a hill and it starts missing and sputtering/power loss there is no white smoke that I can see. The check engine light has never came on during any of this.... here is a list of things that I have recently replaced on the truck trying to fix the problem...

New fuel pump
new filter housing and pressure regulator
new fuel filter
new shower heads on the bottom of pickup tubes
I bypassed the fuel tank selector valve ( thinking debris may be stuck in it)
I blew out the fuel lines also
I am at a loss of what to try next. I am thinking injectors. what do you guys think????

 

Do you have torque pro or forscan? That way you could monitor your hpop when pulling those hills and see if the pressure is dropping.

 

sounds to me like you have a bad under valve cover wire harness connector preventing it from running on all 8 cylinders.

 

No I don’t have either app. But that is a good idea. I will check into that.

 

I think that is the next thing I am look at when I get a chance. The guy I bought it from just replaced the valve pan gaskets. But I know there could still be an issue as I have read on here that the connectors are prone to come loose.

 

Or he could have pinched a wire when he was installing the new ones. It is really easy to do.

Let me find the test for the wiring.....

 

https://www.ford-trucks.com/forums/a...6&d=1564842340


use this to test the wiring. Very helpful, and you don’t have to pull the valve covers to do it

 

I will try that this evening. Thanks

 

I ran the tests and everything thing was good except pins 23 &19 was 4.8 ohms and pins 23 & 9 was 4.8 ohms also. Everything else was 3.4 ohms which is inside the correct range of 2.9 to 3.6. The left power bank feed to injector #6 and #8 ground circuit is above the range(4.8 ohms). I don’t know if that is good or not. I am not really good with electrical.

 

I think I may have found what the problem is. It Looks like I need a new turbo or rebuild this one with a wicked wheel.