Help me diagnose, thanks!

[GC_ATE_]

Hey fellow Subaru owners, I own a GM6, but I'm looking into a 1990 Legacy L to drive around and maybe swap later. So I went to test drive it, great car, drives well on city roads, but once on the highway, it dies. The owner, prior to me driving it said that that was the only problem before hand, and that it was fixed by swapping out the transmission(I don't think the transmission had anything to do with it). But it had no real symptoms, car sounds solid, drives solid, just that once I got on the on ramp and and began to hit 55-60 it lost all power all of a sudden. All the dash lights came on and, I pulled over and started it right back up again. Once started, there was no check engine. Any ideas as to what it may be? I did note that the battery was a little dirty, could it be just a dirty connection? Maybe a fuel problem? Thanks.

[Legacy777]

Welcome to the BBS.

Did the car die just this one time, or was there any other times? Auto or manual trans? I'm going to guess auto...

I had an issue several years ago with an issue where the car would lose power and sometimes stall. It was very intermittant. It turned out to be the MAF sensor. The black plastic bodied MAF sensors found on the automatic trans cars tend to be more susceptible.

[log1call]

Fuel filter is blocked?

[GC_ATE_]

Thanks. And it's an automatic. But it died that one time I was on the highway, and I slowly crept out to the next exit as it would not go over 50 afterward. But once on the streets, it picked up fine again since I wasn't going over 40-45 mph. So a bad MAF sensor or a bad fuel filter could be the suspect?

[HandleWitCare]

How were you driving the car? Hard or were you babying it? Have you tryed to get on the highway pushing it to see if you have any cloged fuel lines? Or like the others have said a dirty fuel filter... As far as the MAF sensor dose it have the stock intake system? Mabey it thinks ur not getting the right air ratio? How dose the air filter look?