GM Engine & Exhaust Performance EFI | GEN I/GEN II/GEN III/GEN IV Engines |Small Block | Big Block |

Lost power after cam swap

Old May 17, 2023 | 06:19 PM
  #21  
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I think this is correct, if y’all can take a look at it and let me know.
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Old May 17, 2023 | 07:00 PM
  #22  
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Pretty bland tune.

The guy did a MAF only tune, zero VE tuning. The timing was raised but it's still pretty mild just looking at the tune, like low 20's for timing. Hard to say where in the timing curve it's using without a log file but it should allow for 24-25 degrees of timing. Burst knock settings are set backwards, they zero'd the table instead of maxing it out to disable burst knock. It also has the engine rpm cut off at 6,700rpm but the transmission is still set to shift at 5,800rpm. Transmission torque mngt is basically turned off, usually not the best with a 4L60e transmission.

We already know it needs larger injectors and a full tune with a wideband oxygen sensor. It also needs the transmission settings adjusted using the blue cat transmission tool to properly setup shift rpm and speed.
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Old May 27, 2023 | 08:38 PM
  #23  
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Finally got around to checking cam timing, due to truck running like absolute crap. On Sunday it started backfiring through the intake, and was just sluggish under 3000rpm. Cam timing was dead on, so I buttoned her back up, checked plugs, coils etc. all looked good. When trying to do a brake stand it just sputters. It went from running decent, to being an absolute disaster.
I’m about ready to run it off a cliff.
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Old May 27, 2023 | 09:57 PM
  #24  
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So the datalog posted is of it sputtering?
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Old May 28, 2023 | 07:13 AM
  #25  
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Yes that is it
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Old May 28, 2023 | 07:59 PM
  #26  
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Check your fuel pressure
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Old May 29, 2023 | 08:18 PM
  #27  
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Checked fuel pressure and it had 55lbs, checked compression on a few cylinders. Could not get one to read higher than 90lbs. Got the driver side head off, can’t really tell anything yet but will take heads to get checked.
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Old May 29, 2023 | 08:50 PM
  #28  
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55psi even under heavy load?
yea 90psi compression isnt good.
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