I have a 1997 Subaru Outback with 180,000 miles. In January I was driving up the steep hill to the ski lift when it completely lost power. I left it on a side street and walked up. Later that day I managed to get it home and figured it must have had water in the fuel. (We had a long stretch of monsoon-type rain and the car sat with only 1/4 tank of fuel, overnight the temps dropped to well below freezing). A month later I got a new fuel pump in the mail, drained the fuel tank, installed it, and it ran fine. 3 months later I am driving normally for about 15 min, I come to a stop, and when I try to accelerate again, there is no power. I put the engine in park and put my foot on the gas. It revs just fine. I try to drive again, no power. This time, the check engine light flashed and then remained on. I left the car on the side of the road and returned a few hours later. It started just fine. I drove until a few minutes after the car got up to temp. Then I completely lost power…engine still running, just no power. It revved fine in park. The only anomalies are these: while driving I noticed the fuel gauge drawing down faster than usual, and then rising again once the engine was off. It was the first time in a month or so that I had driven fast about 40mph. I was on a bumpy dirt road.
I am thinking this could be something electrical as it only happens when the car is warm. Perhaps a bad ground somewhere or bad crank position sensor, O2 sensor etc. It could be a worn engine/bad compression...although I imagine I would hear rough running sounds/ misfires etc from the engine or also have difficulty revving in park.
It’s interesting puzzle and I’m curious to hear your thoughts! Thanks!