Monday morning I couldn't get my 98 Forester to start after sitting for 3 days. The temperature was around freezing. It then started no problem that afternoon and tuesday afternoon as well. Wedneday morning it was 25 degrees and wouldn't start again. I tried to push start it and pop the clucth. It almost started. I was then able to start it with the key. It wouldn't idle and kept stalling. I was able to drive it. It ran really rough even when the engine got to operating temperature. I Drove about 15 miles and had very little power and acted like it had lost a cylinder. This afternoon it started up fine and runs fine. It will be getting cold again tonite and fear I will have the same problem. Anybody have any ideas what is going on.

It sounds like you may have water in your gas tank and fuel lines. Before the temps drop again, head to your local auto store and get some fuel additive for water removal and top up your tank with some fresh gas.

Second that ... sounds like condensation. Never let your tank get below 1/2 full in winter. Check posts for additive warnings tho. I think there have been some messages that some 'dry gas' can harm Subie injector systems. We're not allowed to add de-icers to our county vehicles for that reason.

I'm at a 1/4 tank now. So I'll fill up and see what happens. I wonder if I got allot of water in my tank. A couple weeks ago I ran out of fuel right when my low fuel warning came on. My low fuel warning light is supposed to come on when I got about 2 gallons of fuel left. I wonder if the remaining 2 gallons was actually water and not a malfuctioning fuel warning light.

Methanol based drygas can cause harm to fuel system components. I only use isopropyl based drygas for this reason. I would put a couple of bottles of isopropyl drygas in it and fill it up all the way.

 

When was the fuel filter last changed? Many times the ice will collect in the fuel filter causing fuel delivery problems. How many times has it been run out of gas? That is really bad for the fuel pump, perhaps it's on it's last legs. Has the MIL come on? I would be surprised if it was running that bad as the result of a fuel delivery problem and the MIL wasn't illuminated as the result of a misfire. Makes me lean slightly toward coolant temp sensor.

 

Here in NY we have oxygenated fuel (10% ethanol) year round now, so drygas is obsolete. I have a bottle I will give you.

what is a "MIL"?

Malfunction indicator lamp, OBDII terminology for the check engine light.