phant0mxx
Probationary Member
- 21
- 2
- Feb 5, 2022
-
Las Vegas,
Nevada
I've never seen this behavior before and I'm at a loss.
Engine free revs fine up until ~5000 RPM, where it sputters (video linked below) and I can make it go past 5000 RPM if I very slowly press the gas pedal instead of quickly pushing it.
It also drives fine when there is no load on the engine. As soon as you add load or try to build boost, nothing happens, there is no cut, no jerking, nothing. It doesn't build boost and it doesn't keep accelerating, sort of hangs the revs in place until I let go of the accelerator pedal.
Video:
1st time I do an under 5k RPM acceleration.
2nd time I go past 5k RPM to trigger the issue and hold pedal very little, under 2 seconds.
3rd time I go past 5k RPM again and this time I hold the pedal to accentuate the problem. This time the RPMs started dropping while sputtering, but sometimes the RPMs hold while sputtering, but it never continues to increase in RPM.
4th time I go beyond 5k RPM by very gently pressing the accelerator pedal instead of jabbing it.
Engine idles okay, minus a small oscillation of 50-75 RPM.
ISC works and catches the RPMs before settling back to idle speed.
Parts robbed from a running car:
Smoke tested and no vacuum leaks.
Fuel pressure idling is ~35psi, when accelerating it goes up to ~45psi.
Pressure does not drop while the engine sputters or when driving and trying to load up the engine.
Injectors were cleaned flow tested and rebuilt with new filters.
Ignition timing when locked is at 5º BTDC, and unlocked ~8º BTDC.
Physical timing marks line up correctly.
ECU part number is MD305162 E2T61675 5322 E
ECU components replaced were IC104 and IC107 due to an internally shorted ISC that blew both integrated circuits.
Used original Mitsubishi M5269L ICs and reconstructed burnt PCB traces from ICs to ECU header pins 4, 17, and 18.
Caps look good, no leaks or corroded solder joints nor traces.
I should probably also explicitly say that there's no CEL.
I am open to hearing any suggestions or comments at this point.
Engine free revs fine up until ~5000 RPM, where it sputters (video linked below) and I can make it go past 5000 RPM if I very slowly press the gas pedal instead of quickly pushing it.
It also drives fine when there is no load on the engine. As soon as you add load or try to build boost, nothing happens, there is no cut, no jerking, nothing. It doesn't build boost and it doesn't keep accelerating, sort of hangs the revs in place until I let go of the accelerator pedal.
Video:
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In the video you can see I accelerate 4 times.1st time I do an under 5k RPM acceleration.
2nd time I go past 5k RPM to trigger the issue and hold pedal very little, under 2 seconds.
3rd time I go past 5k RPM again and this time I hold the pedal to accentuate the problem. This time the RPMs started dropping while sputtering, but sometimes the RPMs hold while sputtering, but it never continues to increase in RPM.
4th time I go beyond 5k RPM by very gently pressing the accelerator pedal instead of jabbing it.
Engine idles okay, minus a small oscillation of 50-75 RPM.
ISC works and catches the RPMs before settling back to idle speed.
Parts robbed from a running car:
- PTU (Power Transistor Unit)
- Ignition coils
- Spark plugs
- Spark plug wires
- MAF
- Blow-off valve
Smoke tested and no vacuum leaks.
Fuel pressure idling is ~35psi, when accelerating it goes up to ~45psi.
Pressure does not drop while the engine sputters or when driving and trying to load up the engine.
Injectors were cleaned flow tested and rebuilt with new filters.
Ignition timing when locked is at 5º BTDC, and unlocked ~8º BTDC.
Physical timing marks line up correctly.
ECU part number is MD305162 E2T61675 5322 E
ECU components replaced were IC104 and IC107 due to an internally shorted ISC that blew both integrated circuits.
Used original Mitsubishi M5269L ICs and reconstructed burnt PCB traces from ICs to ECU header pins 4, 17, and 18.
Caps look good, no leaks or corroded solder joints nor traces.
You must be logged in to view this image or video.
I should probably also explicitly say that there's no CEL.
I am open to hearing any suggestions or comments at this point.
