Roweboat32
New Member
- Thread starter
- #1
Yes, I have read the other misfire posts but still have not resolved the problem.
Codes:
Diagnosis Steps:
New spark plugs (gapped 0.052)
New VCT solenoids (B1: Intake/Exhaust, B2: Intake)
Verified IMRC works properly
Replaced 2 problematic lower injectors
Bank swapped all lower injectors
Bank swapped all upper injectors
Bank swapped all coils except cyl3
Cleaned all upper injector o-rings & seats
Cleaned all lower injector o-rings & seats
Cleaned carbon from all intake runners
STP Engine Flush @ last oil change
Compression tested all cyls (w/ throttle closed, yes I know this isn't best practice)
None of the diagnosis steps have made improvements except for carbon cleaning intake ports
Next Steps:
If anyone has any recommendations or pointers I am all ears. Still haven't taken it to a dealer but if these next steps dont work I will.
Codes:
- P0300 (Random misfire)
- P05A1 (Active Grille Air Shutter A Position Sensor Min/Max Stop Performance)
- Cyl 2 & 4 Misfires
- Misfire counts after 10 min hard driving:
- Cyl 1 = 5 - 10
- Cyl 2 = 30 - 50
- Cyl 3 = 5 - 10
- Cyl 4 = 30 - 50
- Cyl 5 = 5 - 10
- Cyl 6 = 5 - 10
- Cyl 7 = 5 - 10
- Cyl 8 = 5 - 10
- Misfire counts after 10 min hard driving:
- Random Flashing CEL @ ~4000rpm & 20% load (varying ECTs)
- Random rich idle (11.5 - 13.0 throttle blip and goes away)
- Random rich/lean swings cruising @ constant throttle input (12.5 - 16.0)
- Random low power (engine sounds rough in high rpms + difference in butt dyno)
- Drove to Denver from Minneapolis and the mountains greatly exaggerated this problem
- Random mild overheating (210 - 230F)
- Drove to Denver from Minneapolis and the mountains greatly exaggerated this problem
- None of the above issues are dependent on each other
Diagnosis Steps:
New spark plugs (gapped 0.052)
New VCT solenoids (B1: Intake/Exhaust, B2: Intake)
Verified IMRC works properly
Replaced 2 problematic lower injectors
Bank swapped all lower injectors
Bank swapped all upper injectors
Bank swapped all coils except cyl3
Cleaned all upper injector o-rings & seats
Cleaned all lower injector o-rings & seats
Cleaned carbon from all intake runners
STP Engine Flush @ last oil change
Compression tested all cyls (w/ throttle closed, yes I know this isn't best practice)
- 1: 235 (low battery)
- 2: 235 (low battery)
- 3: 240 (low battery)
- 4: 230 (low battery)
- 5: 230 (low battery)
- 6: 240
- 7: 245
- 8: 250
None of the diagnosis steps have made improvements except for carbon cleaning intake ports
Next Steps:
- Di-electric grease on porcelain of spark plugs
- Get motor hot, smoke test intake manifold
- Test wiring going to coil packs
If anyone has any recommendations or pointers I am all ears. Still haven't taken it to a dealer but if these next steps dont work I will.
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