Subaru outback stalling

Help! My 2000 Subaru Outback automatic, with 95,000 miles is intermittently stalling. No check engine light, no sputtering, engine temperature & oil pressure fine; it will just be running and then it isn’t. It has happened with a 1/4 tank gas and with a full tank of gas. Primarily it has happened after driving around on a hot day, with some highway driving, city driving, running errands- so stopping for a while, then when I head home and gain altitude (another 2000-2500 ft), it will stall when I take my foot off of the accelerator to make a left turn, or go around a blind right curve, but not every time. When it has stalled once, it tends to repeatedly stall when I take my foot off of the gas. It always starts right back up again with no problem. It happened once in town right after I filled up with gas, but didn’t repeatedly stall after that.
It has been to my mechanic 3 times and no codes come up with scan. The AF sensor (idle control valve) was replaced twice, throttle body cleaned (although not bad), crank sensor checked, fuel trim checked, wires, battery checked, hoses checked, reprogramming of ECU checked- not needed, no recalls/reflashes, nothing found.
Any brilliant ideas?? I don’t want to end up stranded on a lonely mountain road with fires approaching, or getting broadsided when it stalls in a left turn.

When it stalls, does the dash light up with the OIL or ALT/BATT light?
Or does it seem like you’ve just pulled the key out of the ignition when it dies, with no lights on your dashboard present?
If it dies with no lights, does the dome light still come on when you open the door?

Those are important clues.

No lights come on when it stalls. As soon as I turn off ignition and turn it back on, everything lights up the way it normally would when starting the car. no lights stay on any longer than normal. I haven’t tried opening the door when it stalls, as it does start again right away.

I’m guessing this is something associated with the fuel supply. Since turning the ignition on and off, that points to an intermittant electrical problem. The fuel pump relay would be the main suspect. The fuel pump would be second on the list The fuel pump could be failing as a result of an electrical problem or that the inlet is clogged. Did this start happening all at once, say after you purchased gasoline at a place you usually don’t? Or did you notice something wasn’t quite right and it gradually got worse?

Stalling can be caused by a lot of things. But now it’s a mystery game. You have to eliminate the suspects one by one. To solve your mystery, suggest to eliminate the above as potential suspects.

It sounds like your ignition switch may be the problem. Let me see if I can find the schematic to your car.

Edit: Yeah, even if your car has an alarm system with an inhibitor, all it inhibits is the starting function. In other words, if alarm system got confused and somehow inhibited operation, it would not inhibit driving the car if it were already started - so any of the interlocks and the alarm inhibitor is not your problem.

Since your lights all turn off, I strongly suspect your ignition switch is the problem.
Your car radio is tied to the ignition switch, I believe. Does that go off when your car stalls?

@GeorgeSanJose, I don’t think it is fuel or spark related:
I say that because, when it stalls, the dash goes out completely. The oil light does not turn on as it would when the car is still in the ‘run’ position but not actually running. That’s the same condition as turning your key in the same position as the position before ‘start’ .

@RemcoW, I may have misunderstood what MtGirl said. I thought she meant that no unexpected dashboard lights oame on when it stalled. You are right that if the the car has idiot lights for the alternator and oil, they should come on when it stalls. That indeed would be an indication of an electrical problem and quite possibly with the ignition switch or a faulty main power supply relay.

MtGirl: Please clarify whether the car’s electrical system continues to work after the stall. Does the radio work? Does the dome light work? Are there any guages on the dashboard that work, like the gas tank guage?

The only sign I have that the car has died is that all of a sudden I have no power brakes, or steering, and then I realize that the engine isn’t running. Since I am usually listening to the radio, I don’t think that goes off. It has only happened during the daylight, so I really wouldn’t notice if dash lights, running lights were off. I definitely have not seen any trouble lights on the dash when it dies, as I have looked for that. It always starts right away- I haven’t had any problem with ignition. It hasn’t shown any other signs, so I would have to say it started right away and hasn’t come on gradually. This has been happening intermittently for about a month, but I don’t drive a lot. It hasn’t happened on a cool day. The fuel supply was checked by the mechanic.

Also, i think the gauges do continue to work, as I have looked at temperature and oil pressure, although I don’t know whether they would just freeze where they were.

@Mountaingirl … you may have to leave your car at the repair shop for a few days. Intermittant problems are always difficult for both the owner and the repair shop. Consier to arrange to leave it there and ask them to test it several times a day. They’ll eventually get it to stall, then they can figure out the cause. Maybe you can rent another car in the meantime.

The only other idea I can think of would be to Google “Subura Outback Stalling”. Sometimes that will lead you to a dicussion forum somewhere on the internet where somebody else may have already had the problem and figured it out.

Best of luck.

If the radio isn’t dying, I don’t think it is the ignition switch, nor a battery connection.
It could be a thousand other things, unfortunately.

Crank sensor, maybe. They go bad sometimes where they become intermittent but you’d hate to swap that thing to find out it is one of the other 999 things…

This is a good one.

The trouble might be with the fuel pump relay contacts. Fuel would get cut off and engine would die. The oil pressure warning light should come on at some point along with the alternator warning light if that is the case.

Another thought is the trouble may be due to a faulty chassis ground though that is pretty far fetched and wouldn’t explain the radio working, if that is true. The most logical thought is the ignition switch or possibly a problem with the fuse panel in the dash after the switch. Perhaps a section of the panel has a problem and not all the fuses are losing power.

Thanks for the ideas. The mechanic says that many of the things it could be should show up on a scan and yet nothing does; it is very mysterious. Sooner, or later I will get it to stall for them.

Mountaingirl, I am having this exact problem. Did you ever solve this?

@thatmatt254–Mountaingirl has not posted anything at all in this forum since July 2012, so it is very unlikely that she is still monitoring this thread.

I suggest that you post your own question, in your own new thread, by clicking on the red “New Discussion” button at the top right of your screen.

I think your best bet is with the fuel pump causing the issue. You may be able to prove it before changing it out by monitoring the current while the trouble is occurring to see if there is a change. Here is a link for a tester at a reasonable cost you could install to do that. If the current drops severely then maybe the fuel pump relay is at fault. If the current goes higher than normal, then the fuel pump may be locking up for some reason.

http://www.harborfreight.com/catalog/product/view/id/6669/category/428/