2004 Legacy Outback, AT, with H4SO U5 engine, non-California emissions. 195k miles.
TL
R – cranks, hard time starting, if it starts stalls right away. Has fuel, spark, ignition, and compression.
Background: Purchased car as a no start. Previous owner stated car stumbling/ bucking and then died while driving. Towed to shop (specializing in Subarus) they couldn’t figure it out. Note on car key from shop was “won’t accelerate”. Mechanic diagnosis was “needs an engine or a computer”.
As of right now car cranks and occasionally will catch if playing with gas pedal but will stall out almost immediately when it starts. Got it once to idle for 10 seconds, no change in RPM when applying throttle. This was after having it sit for a week.
Troubleshooting already done
Other troubleshooting steps
Replaced two fuel injectors (for troubleshooting purposes, in the case they were clogged. No improvement.
Fuel pressure regulator, presumably good. Holds vacuum, however I did see a small pool of liquid (presumably fuel) behind the throttle body inside the intake.
Next steps:
Unsure on what to check next. I want to say I doubt it’s the ECM, but I never had a car with a bad ECM. I did not see a diagnostic step where it states to replace ECM.
I want to say it is something fuel related, due to the hesitation and bucking as mentioned by the previous owner. However, it does feel like (possibly intermittent/ starting to fail ignition switch, as car dies right away when not actively cranking)
Any recommendations on next troubleshooting steps?
Thanks
TL
R – cranks, hard time starting, if it starts stalls right away. Has fuel, spark, ignition, and compression.Background: Purchased car as a no start. Previous owner stated car stumbling/ bucking and then died while driving. Towed to shop (specializing in Subarus) they couldn’t figure it out. Note on car key from shop was “won’t accelerate”. Mechanic diagnosis was “needs an engine or a computer”.
As of right now car cranks and occasionally will catch if playing with gas pedal but will stall out almost immediately when it starts. Got it once to idle for 10 seconds, no change in RPM when applying throttle. This was after having it sit for a week.
Troubleshooting already done
- Compression test - good (150psi) (Cylinder 4 lower due to HS leaking). Timing belt replaced around 2 years ago.
- Good spark on all cylinders. Re-gapped spark plugs from 0.9 to 0.32 per manual. Did look a bit blackish and wet due to troubleshooting. No improvement.
- Air filter looks good and clean, no obvious vacuum leaks in intake.
- Cleaned IAT, MAP, and MAF
- Fuel pressure – 42-45 psi upon startup and when cranking. All fuel injectors are getting voltage/ ground, tested and firing
- Crank and cam sensors – Tested and are within specs. Crank sensor had some dirt on it, cleaned it, no improvement. Replaced crank sensor from Junk yard car, no improvement. (I can see the tachometer goes up on instrument cluster, and it does occasionally start, so I doubt it’s the sensor, however, I did get once a DTC of P0335 (Crank position sensor) after extended cranking. Verified that the wiring was good from connector to ECM.
- Battery, older but holding voltage and attached to a slow charger. No change with different battery or when boosting with other battery.
Other troubleshooting steps
Replaced two fuel injectors (for troubleshooting purposes, in the case they were clogged. No improvement.
Fuel pressure regulator, presumably good. Holds vacuum, however I did see a small pool of liquid (presumably fuel) behind the throttle body inside the intake.
Next steps:
Unsure on what to check next. I want to say I doubt it’s the ECM, but I never had a car with a bad ECM. I did not see a diagnostic step where it states to replace ECM.
I want to say it is something fuel related, due to the hesitation and bucking as mentioned by the previous owner. However, it does feel like (possibly intermittent/ starting to fail ignition switch, as car dies right away when not actively cranking)
Any recommendations on next troubleshooting steps?
Thanks