7.3 can run very smooth but there is a lot that not make it smooth and make you wonder what to do next.

close to 30 years now of when it came out and in the last 2 years i have learned more than i wanted to and thought i would share a few things.

Its not always injectors, wiring or fuel pressure. Dont fall for the trap just yet. do a few things to rule out everything before unloading that fat wallet

if you have an auto, you wont have as much of an issue as the TC isolates some vibes.

got a stick? 7.3 is more temperamental with a stick.

Bad ujoint
drive shaft support bearing howling
shoe dragging
drive shaft to pinion caps worn allowing shaft to be off center
bad pilot bearing
bad clutch disc hub
worn input shaft on trans and input bearing
worn pocket bearing in trans
fan clutch
bent fan
bad PS pump
WP with worn bearings impeller cat hit cover or pump housing
tensioner bearings
idle pulley bearings
too little belt tension
Alt bearings
Vac pump bearings
worn belt
AC bearing
failed or loose harmonic Balancer ( sounds like needle scaler in the cab and or cab shaking )
front axle bearings in hubs howling
hub bearings howling
worn tires
washboard type roads

So, what do these vibrations do?

thats one example but imagine it in a bowl

now think about the HPOP and fuel bowl doing the same thing allowing for air intrusion, making you think its bad injectors

 

By the time I get everything replaced and the truck totally refreshed. It will be time to start over.