Last month, I posted this problem: I start my 87 Loyale which runs perfect at this point(Carbuerated Hitachi) and drive approx 1/4 mile (end of driveway.) Then it starts sputtering and I feather the gas to try to keep it going and it sputters and tries and tries and eventually dies.

 

The consensus before was that it was a fuel pump so I bought a new one and it did the same thing. I then took the pump, strainers, etc out of my 86 Wagon (which works fine) and put it in there. Same thing.

 

Also took the Carb out of the 86 which works fine also and put it in there. Same thing.

 

wtf??????

recently, after washing the engine, i couldnt get my 86 carbed wgn to idle...finally, i found a vacuum hose that was just barely not on, pushed it completely on and no more problems....

A couple years ago I had an '86 Izuzu Trooper that had sat for 6 years, after we got it going it started doing what your subie is doing. Did all kinds of things trying to fix it including changing the fuel pump. It ended up being a bunch of rust in the gas tank. It would plug up the pick-up screen inside the tank after driving a few miles, then sputter and die. I'd let it sit for an hour, then it would start right up and run good for another few miles. Finally fixed it by flushing out the gas tank. Also had the exact same problem and fix with an old '65 Massey Ferguson tractor. Good luck, let us know what you find.

Make sure the fuel pump is getting the proper voltage (12 volts) when this happens. Measure across the two leads to the pump when checking it.