alibaba2727
New Member
- Joined
- Jan 23, 2026
- Messages
- 1
- Vehicle(s)
- Subaru levorg 2018
I’m looking for insight from anyone who’s experienced a similar issue on an FA20DIT Subaru.
I have a 2018 NZ-new Subaru Levorg (FA20DIT, CVT, stock). The main symptom is a severe loss of power on initial acceleration, particularly when the car is cold or under load (uphill or reversing uphill). The car may begin to move, then suddenly lose all power and decelerate. In some cases I can have the accelerator fully depressed with the car not moving at all for an extended period (up to ~30 seconds), after which power suddenly returns and the car accelerates normally. There are no warning lights on the dash. The issue is very obvious to me as the driver but has been intermittent and difficult for mechanics to reproduce.
This issue first appeared around six months before the engine failed. I returned the car to a mechanic multiple times during that period, but no fault could be found and no codes were present, so I continued driving it. The engine later developed knocking and was diagnosed as having run a bearing, and the engine was fully replaced. The original drivability issue returned immediately after the engine replacement and remains unchanged.
Subaru dealership diagnostics later identified a consistent P1604 (Startability Malfunction) fault. Fuel pressure testing showed that pressure would bleed down to zero after the car was left overnight. The in-tank fuel pump assembly was removed and found to have a leaking regulator and slow priming, and the complete pump assembly has since been replaced. The issue persists exactly as before.
At this point I’m trying to determine whether others have experienced similar “dead pedal then sudden surge” behaviour on FA20DIT Subarus with no warning lights, especially when cold or under load, and what the eventual root cause turned out to be.
Any shared experiences or diagnostic suggestions would be greatly appreciated.
I have a 2018 NZ-new Subaru Levorg (FA20DIT, CVT, stock). The main symptom is a severe loss of power on initial acceleration, particularly when the car is cold or under load (uphill or reversing uphill). The car may begin to move, then suddenly lose all power and decelerate. In some cases I can have the accelerator fully depressed with the car not moving at all for an extended period (up to ~30 seconds), after which power suddenly returns and the car accelerates normally. There are no warning lights on the dash. The issue is very obvious to me as the driver but has been intermittent and difficult for mechanics to reproduce.
This issue first appeared around six months before the engine failed. I returned the car to a mechanic multiple times during that period, but no fault could be found and no codes were present, so I continued driving it. The engine later developed knocking and was diagnosed as having run a bearing, and the engine was fully replaced. The original drivability issue returned immediately after the engine replacement and remains unchanged.
Subaru dealership diagnostics later identified a consistent P1604 (Startability Malfunction) fault. Fuel pressure testing showed that pressure would bleed down to zero after the car was left overnight. The in-tank fuel pump assembly was removed and found to have a leaking regulator and slow priming, and the complete pump assembly has since been replaced. The issue persists exactly as before.
At this point I’m trying to determine whether others have experienced similar “dead pedal then sudden surge” behaviour on FA20DIT Subarus with no warning lights, especially when cold or under load, and what the eventual root cause turned out to be.
Any shared experiences or diagnostic suggestions would be greatly appreciated.
