Delphi 4J ECU Tuning
Engine control unit used in 3 supported models from 2 makes.
Holden with the Delphi 4J
All Holden tunes- Holden Rodeo2002+3.0 TD (4JJ1)AutoTuner
Isuzu with the Delphi 4J
All Isuzu tunes- Isuzu D-Max / Vcross2006+RA,RC · 3.0 TD (4JJ1)AutoTuner
- Isuzu MU-X2013+3.0 TD (4JJ1)AutoTuner
About Delphi 4J tuning
The Delphi 4J engine control unit is supported in 3 models from Holden, Isuzu. We read, modify, and flash it with AutoTuner, then verify the result on our Dynojet 424xLC2 in Jenison, MI. A custom calibration optimizes fueling, ignition timing, boost, and torque limits for your exact build.
Don't See Your Vehicle?
These lists cover off-the-shelf tuning platforms. We also do standalone ECU installs and custom calibrations, so reach out and we'll tell you what's possible for your build. Compatibility data last updated 2026-09-24.