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7.3 running rough

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I'm lookin at one of my drivers trucks. its a 95 f250 with a 7.3

 

truck runs real rough on idle, but only after idling for a couple minutes. what happens is you start the truck, truck runs great, no misfire or anything and it revs right up and even drives nicely too, but after a few minutes the CEL comes on, and the truck lets out a huge puff of white/grey smoke, and the truck runs like its misfiring. I try to read the codes for KoEO, with my global ob2 reader and no codes are shown, when i go to read them with the truck running it wants to die every single time.

 

truck has no leaks, the MAP sensor hose seems intact, my driver just changed the fuelfilter to see if it would change the condition, and it still happens. it was happening intermittently at first, and now its constant. any help or steering me in the right direction would be great, thanks

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There's not enough info here to help you out. Get the performance diag sheet and go through it, step by step.

 

What's fuel pressure?

 

What does a fuel sample look like in a glass jar?

 

Are MAP, BARO, and EBP all 14.7 KOEO?

 

How does the buzz test sound?

 

Have you checked the VC and UVC harnesses?

 

What scan tool are you using?

 

If you don't get anywhere, try filling the FF with Stanadyne and see how it runs.

 

How do the batteries and cables look?

 

Good Luck!

 

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dont have the tool to test fuel pressure, nor a scan tool to read what the voltages are. i dont have a book to see what pins go where, etc. scan tool is just a little code reader.

 

fuel sample is clear in the bowl, lift pump operates fine (fills the bowl extremely quick..almost too quick as my parking lot found out..) and i dont think i heard the buzz test this last time..so i'm going to double check again.

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no buzz test, turn the key on and you hear the clicks of the solenoid kick on..few seconds later a loud click. almost like a circuit breaker tripping..

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well i was able to pull the codes, and also do a buzz test (had to borrow a scan tool)

 

koeo codes i got were p0273, p0274, p1265, p1275, p1291. all codes point to cyl #5, but i'm thinking it may be electrical instead of just a failed injector. buzz test, cyl 5 was way too quiet, so its all pointing to the circuit or injector #5.

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well i was able to pull the codes, and also do a buzz test (had to borrow a scan tool)

 

koeo codes i got were p0273, p0274, p1265, p1275, p1291. all codes point to cyl #5, but i'm thinking it may be electrical instead of just a failed injector. buzz test, cyl 5 was way too quiet, so its all pointing to the circuit or injector #5.

Those have 2 connectors for the injector to VC gasket. I'm betting one is cooked. Make damn sure you check for shorted glow plugs BEFORE putting any new parts on if the connectors are cooked...don't ask me how I know...

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