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Rough idle

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Old Apr 23, 2025 | 05:32 AM
  #1  
kmiller7351's Avatar
kmiller7351
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Trailering
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From: The other gambling paradice
Rough idle

So I had a mech replace the #8 injector. pulled out of shop and started acting up again. So, I took it back and they may have replaced injector again since it was considered under warranty. On the scanner the #8 injector is flat line other with other injectors, then drops off. They said it was a weak spring and would act up when motor gets warmed up (usually around 13 min) and they discovered by moving the spring or observed the issue. Also had blue smoke when acting up. When I start and go when cold its fine until it warms up. So still runs rough after warmed up sometimes cold start just idling will up. Occasionally after restart when warmed up might not do it at all. So, with all that, weak spring last diagnosis, possible cracked head, loss of compression assumption, is there any definitive answer? I don't think I have the skill set to pull head off and replace **** correctly. Do I just continue to accept this and keep driving. Don't want to spend another $$$$ to discover it wasn't this now.
EGR Delete, bullet proof, new glow plugs, Crank and camshaft position sensor replaced.
Advice? or do I know the answer

Can exhaust blockage cause an imbalance code. i have been chasing codes, 2 mechanics 1 replaced #8 injector as far as i know, replace crank and cam shaft sensor, all glow plugs trying to resolve a rough idle after it warms up. Been told a cracked head, loss of compression in #8, bad injector.

I had an exhaust clamp break so I wrapped up with muffler tape only what seems to have gotten worse idle wise after several minutes of sitting with so surging which is new with taped exhaust. milage seems the same. I had egr cooler replaced, egr delete, and it's around 270000. So would a clogged exhaust cause problems. Do I cut out a section to see or is that a waste of time?
Also, when I put my foot against exhaust pipe there is no resistance
 
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Old Apr 23, 2025 | 06:40 AM
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99powerstrokedF250
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Need some info on your truck before we can give you ANY help.

You talk about glow plugs so I know you're talking about a diesel. Suggest you get it to a REAL diesel mechanic who is going to do some actual diagnosis, don't fire the parts cannon as you'll just be throwing away money.

Whether it is a 7.3 or a 6.0 can change the diagnosis, we need to know which you have. If you're losing injector contribution I don't think it's low compression, I would think it has to do with the injector or the harness leading to it.

Depending on which motor you have, you may want to head down to the diesel forums below - they'll have more detailed information for you.
 
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Old Apr 23, 2025 | 01:04 PM
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Since you say it's been bulletproofed, is it safe to assume it's a 6.0? I know it's not a 7.3 since they never had an EGR.
 
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Old Apr 23, 2025 | 02:44 PM
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I have a 6.0, about 270000 miles
 
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