1994.5 - 1997 7.3L Power Stroke Diesel  

7.3 Running Rough

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Old 01-10-2023, 10:39 PM
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7.3 Running Rough

Hey guys, I own a 96 7.3 powerstroke. I bought it and it started smoking everywhere. Running awful. I have replaced the injectors, Icp, cps, valve cover and Harness. It sounds like it has an huge knock and when i rev it, it sounds like a bearing is playing ring around the rosey inside the block. Also Glowplugs have been replaced I know it won’t help but just to throw it out there. Any help would be awesome before I sell the turd lol.
 
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Old 01-11-2023, 09:05 AM
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All that work and you will have air in system that needs to clear out in about 100 miles of driving it.


sounds low on fuel pressure maybe, loose flywheel or an exhaust leak on manifold ( drivers side rear bolt missing on manifold?)

that roughness could be the harness on drivers side valve cover can get chaffed over the years

did you do a compression test?

can ohm it out with schematic here
https://www.ford-trucks.com/forums/1...load-test.html

 
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Old 01-11-2023, 09:10 AM
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Originally Posted by knottyrope
All that work and you will have air in system that needs to clear out in about 100 miles of driving it.


sounds low on fuel pressure maybe, loose flywheel or an exhaust leak on manifold ( drivers side rear bolt missing on manifold?)

that roughness could be the harness on drivers side valve cover can get chaffed over the years

did you do a compression test?

can ohm it out with schematic here
https://www.ford-trucks.com/forums/1...load-test.html
I know it sounds dumb and I made a huge mistake, but no I did not do a compression test. If I could go back in time before dumping over 3 grand in the truck I would have trailered it to the shop and paid $200 for a test to tell me exactly what’s wrong with it. I have replaced the balance cover harness. And it’s getting fuel also there is no exhaust leak.
 
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Old 01-11-2023, 09:23 AM
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Did you crank it by hand after the injectors were done? When you yank the injectors the cylinders fill with oil. You need to leave the glow plugs out and turn it over by hand to clear the oil so you dont hydro lock. Some people leave the GP out and put the valve covers on loosely and bump it over. If you didnt do that and you didnt bend a rod shes gonna smoke like mad. Like the previous poster said there is a ton of air in the high pressure oil system after all that work. It will take time to work it out and idling wont cut it it will purge some but it needs to be driven. Was there a bunch of blow by before all this went down?
 
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Old 01-11-2023, 09:28 AM
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Originally Posted by 96SD
Did you crank it by hand after the injectors were done? When you yank the injectors the cylinders fill with oil. You need to leave the glow plugs out and turn it over by hand to clear the oil so you dont hydro lock. Some people leave the GP out and put the valve covers on loosely and bump it over. If you didnt do that and you didnt bend a rod shes gonna smoke like mad. Like the previous poster said there is a ton of air in the high pressure oil system after all that work. It will take time to work it out and idling wont cut it it will purge some but it needs to be driven. Was there a bunch of blow by before all this went down?
There was so much smoke it wasn’t even funny. I literally smoked out the highway cars had to stop because they could not see. I did crank it by hand when install new injectors. Crank it probably 20 times. The injector cups are fine as well.
 
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Old 01-11-2023, 09:48 AM
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after injectors, its going to smoke some

pull valve covers, remove GPs, and get a compression tester in that hole

Only takes an hour to do and we will know if all this was worth it or not
 
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Old 01-11-2023, 09:49 AM
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Originally Posted by knottyrope
after injectors, its going to smoke some

pull valve covers, remove GPs, and get a compression tester in that hole

Only takes an hour to do and we will know if all this was worth it or not
I’ll try it out. Thankyou
 
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Old 01-11-2023, 09:50 AM
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The smoke could be from some oil blowing into the exhaust from the ejector swap, and burning from the exhaust heat. I should clear up in a few miles.
 
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Old 01-11-2023, 11:00 AM
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Originally Posted by farmert
The smoke could be from some oil blowing into the exhaust from the ejector swap, and burning from the exhaust heat. I should clear up in a few miles.
if oil in the down pipe like mine was (i removed the rear injectors first LOL) when i hauled my camper for first time and EGT hit 1200, there was a huge cloud behind me for a couple miles and clear up after. I was getting nervous at that point of maiden voyage
 
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