Hi everyone,
I've been troubleshooting a power issue with my 1994 Mitsubishi Mighty Max (6G72 engine) and wanted to share what I've done so far and seek some advice.

[top]Steps Taken:

  1. Valve Cover Gaskets: Replaced due to severe leakage.
  2. Spark Plugs: Replaced to ensure proper ignition.
  3. Cleaning: Thoroughly cleaned the MAF sensor, IACV, and intake.
  4. Injectors: Replaced with injectors from a 3000GT (same engine type).
  5. Fuel System: Verified no vacuum leaks by spraying carb cleaner around the engine bay.
  6. MAF Sensor Replacement: Installed a Delphi AF10323 MAF sensor from O'Reilly's. The engine starts but dies after about 3 seconds with the new sensor. Disconnecting the MAF significantly improves performance, indicating the old MAF might be faulty.
  7. checked intake tube: for rips and tears and found nothing.
  8. Checked wiring: I inspected the wiring to the MAF and found no issues.

[top]Issues/Theories:

  • The engine won't idle long enough for the ECU to retrain.
  • Suspect the new MAF sensor might be a dud.
  • The engine will run with the old MAF but won't go over 50 and has issues starting when the truck is at running temp.
  • Unplugging the MAF gives the truck significantly more power, it can hit 80 no problem. However it burns comical amounts of fuel and smells really bad.

[top]Questions:

  • Has anyone experienced similar issues with replacing MAF sensors?
  • Could there be other underlying issues I should check?

Any advice or suggestions would be greatly appreciated. Thanks in advance!