I had a hair-raising incident yesterday. My engine (automatic transmission) cut out while driving at around 30mph on a main road, just like a manual stalling. It restarted on the first attempt as soon as I'd realised what was happening, after putting it into parking gear etc.
After this, it drove but struggled to shift itself above second gear and struggled to accelerate. If I accelerated a normal amount, the revs would lurch and bounce up and down alarmingly without the car gaining speed like it was stuck bouncing between gears. I put it into "2" and drove slowly, and it seemed better, but even then the revs occasionally went up or down for a moment with no obvious reason.
I was down to about 20% fuel, and this is a country where fuel quality can be low (sometimes literally watered down). I crawled along to a petrol station and refueled - after refueling, it was a little slow to accelerate at first especially going up hill, but after about 15 minutes on the road seemed pretty normal.
After letting everything cool down, I checked transmission fluid levels*, and they were normal. No problems at all shifting between positions on the PRND2L stick, either - reverse reversed, park parked, drive drove, 2 and L behaved as expected.
Could what happened be explained by low / bad fuel or should I do other checks as well?
*oops, I should have checked transmission fluid while the engine was idling, not after letting it cool down (according to the Haynes manual for this car and model). Actually, my transmission fluid was low - topped up now.