1994.5 - 1997 7.3L Power Stroke Diesel  

7.3 engine woes

  #1  
Old 07-14-2014, 08:10 PM
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7.3 engine woes

Hey everyone.

I have a 96 F350 with a 7.3l Power stroke with 189k miles.
Okay, here's my problem and bear with me.

my truck has started to take a little longer to start and smokes like a train. Smoke is blueish. She runs a little choppy (though I understand that it does naturally being a 7.3) but even after its warmed up its still choppy. When accelerating it's choppy up until 2500 rpm. After 2500 rpm, it smooths out and runs like warm butter down a knife.
Sorry, I felt being descriptive lol.

Any ideas?

It's got a different PCM and IDM on it. Just replaced one of the injectors and UVCH on passenger side. No codes, buzz test clean, cylinder contribution test good.
 
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Old 07-14-2014, 08:21 PM
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Sounds like its time for GP's and injectors.
 
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Old 07-15-2014, 03:57 PM
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Could a bad IPR cause any of this?
 
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Old 07-16-2014, 03:06 AM
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What did you use to do the buzz test, do you have AE, Scan Gauge or Torque App?

If you have one of those, post the ICP and IPR numbers. Also check fuel pressure at idle, needs to be 50-80psi. Check fuel filter (is it black?) and clean the FPR screen in the fuel bowl. Just some things to check to get started with a baseline.

Sounds like glow plugs and GPR are a must as Glenn said.
 
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Old 07-16-2014, 12:21 PM
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I I had a shop do it for me with a SnapOn. Never told me any reading specifically, just performed the tests and the only odd one out of it all was the cylinder contribution test for Cylinder number 5. Swapped it out for a different injector I had in another good engine with new orings and its still smoking. Although I do hear a distinct "Tap" sound come from only the passenger bank. I know the motor isn't a quiet one and that they make noise but this tap was weird.
Any who, my fuel pressure last I checked 2 days ago was 45 psi.

Fuel filter is new and not black
 
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Old 07-16-2014, 04:17 PM
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The tapping is probably just air working it's way out. It takes time
 
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Old 07-16-2014, 05:09 PM
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How do I correct the fuel pressure issue besides the BB mod?
 
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Old 07-16-2014, 09:30 PM
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Electric fuel pump and turn up the regulator.
 
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Old 07-16-2014, 10:38 PM
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Well I got my hands on a Snap On Solus Ultra. Ran another cylinder contribution test and cylinder 5 showed up again but the injector buzz test shows all 8 injectors test great.

What now?..
 
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Old 07-16-2014, 10:42 PM
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Check the UVCH plugs, and pull the valve cover and check the wiring harnesses under there. You are looking for burnt or melted pins in the plugs and burnt or melted wires under the valve covers.
 
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Old 08-22-2014, 04:01 PM
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Turns out it was a bent connecting rod. Replaced and smoke went away. Thanks you guy!
 
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Old 08-22-2014, 05:21 PM
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Originally Posted by Smokey_7.3
Turns out it was a bent connecting rod. Replaced and smoke went away. Thanks you guy!
How'd you find that
 
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Old 08-22-2014, 05:53 PM
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Got a picture if the rod ?
 
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Old 08-22-2014, 06:07 PM
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Originally Posted by MOOSE_MACHINE
How'd you find that
Compression test, I reckon.
 
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Old 08-22-2014, 08:46 PM
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Yeah. I went out and bought a compression tester and all were at 500+ while number 5 was around 290-310. Took The head off to check it out and the piston didn't rise to TDC.
 

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