I was driving my 1990 240 (280K + mi) from a 600 mi trip. Filled up with gas and drove about 100 miles when engine lost power. Pulled off road and car idled fine but when throttle increased engine would not speed up. Thought maybe a clogged fuel filter. Went to auto parts and bought new one and installed it in parking lot where I had stalled. Started engine and it ran fine and drove for about another 100 - 150 miles when same thing happened again. Stopped let engine idle for awhile and for some reason after about 10 - 15 min. it ran again. This happened again one more time before getting home. Now getting ready to trouble shoot this problem, car runs fine now but have not driven it a few miles to see if it might happen again, which it did not. Not sure that I had bad gas, or is prefilter clogged or what. Need help on what could have caused this.