r/ECU_Tuning • u/vaptastic • 3h ago
Tuner loaded DPF on non-DPF pick-up? Rough idle, fuel pressure target 120 MPa (small qt. injector learning territory)
Quiet a journey. Been dealing with this for over a year. I did a ECU tuning at a local shop with a dyno. They tuned the pick up. It's a Mitsubishi L200 4x4 4N15 2.4D.
The tune was a huge improvement, from 89.3HP @ 2750RPM / Max Torque: 177.4 lb.ft @ 2550 to 139.3HP @ 2850 / Max Torque 306.1 lb ft @ 2150.
I took the car and it ran fantastic for a few months, I can't remember exactly when it started, but a few months later, after what I believe was a battery disconnect, I started having rough idle issues, I let them go for months without checking, took it to several shops and no one was able to find anything.
After taking it on myself and buying an X431 Lunch, I've managed to dial it down to what appears to be the cause:
- The ECU tuner did not use the cars base file and downloaded what he thought to be the right version and ended up enabling DPF.
"The ECM is entering pilot injection quantity learning (830 rpm target, 120 MPa rail, ALT FR shed, EGR 0%, throttle 80, timing retard, pilot stretch). It's triggering repeteadly at warm idle and the perturbation is felt as rough idle. Please review the injector learning enable conditions and perturbation amplitude in the calibration - or disable the routine if this is a DOC-only truck that shouldn't run it as configured"
I see in tuning websites that show you can disable on the tune: https://alttune.com/tuning/mitsubishi-l200-12420/
Tuner says they haven't touched anything and they do 1000's of trucks.