Engine Turns Off Randomly

[ParanoidAndroid]

Anyone have problems with their older model (early 90s) Subaru shutting off
at seemingly random occasions? I can't figure out what's wrong with my
Legacy and neither can my mechanic. It starts fine, runs fine, everything
seems ok but out of no where the engine just stops. No warning, no
sputtering or anything, just shuts down. When I pull over and place it in
park the engine turns back on like nothing happend. I'm thinking it has to
be a sensor or some kind of computer problem. Anyone have a similar
problem or know what could be wrong with my car? Any help would be
greatly appreciated. Thanks.

 

[Rick Courtright]

Anyone have problems with their older model (early 90s) Subaru shutting off
at seemingly random occasions?

Hi,

Some far-fetched ideas to try after you exhaust the "usual suspect"
list:

Your ignition switch may be dirty or worn. My "door dinger" works
intermittently, and the headlights would go "off" when switching from
low to hi-beam when I got my '90 Loyale. It lived its "first life" in a
very dusty environment, and both problems responded well to repeated
applications of aerosol contact cleaner to the respective switches
(available at the auto parts store.) My "4wd" light on the dash
(switchable system--switch on shift knob) is also intermittent--same
apparent cause, but it responds better to a shot of WD-40 than the
contact cleaner.

My g/f carries around a huge assortment of trinkets on her key ring--I
don't know how much they weigh, but mechanics have told me this can put
extra strain on the ignition switch and cause wear (which could then
cause an intermittent open circuit over bumps and such.)

Good luck finding the problem! Intermittent stuff's always the worst...

Rick

 

[S]

Hi PA!

Anyone have problems with their older model (early 90s) Subaru shutting off
at seemingly random occasions?

While I haven't seen this on a Legacy, I have had similar problems
with other makes and models. Usually has turned out to be ignition
components failing. I'd try swapping in another ignitor module for
starters. I think it is located on the fire wall behind the engine on
these cars; perhaps someone on the group knows for sure?
As Rick suggests, your key switch could cause this symptom as well,
especially a "well used" one. Not too hard to replace the switch; IIRC
just a couple screws holding it to the back side of the lock
cylinder/steering lock mechanism. Unplug the connector, and it's out.
Other things to look at might include the injector resistor pack
(loose wiring), the fuel pump (again, loose wiring), or even the large
connectors for the engine wiring harness (plugged in all of the way?
Water or other contamination present?). ECU seems unlikely, but
possible I suppose, and it _could_ be something as simple as a loose
fuse in the fuse box, so inspect that as well.
Alas, the easiest way to diagnose problems of this sort is to swap in
"known good" parts until the problem goes away; prohibitively
expensive if you're buying new bits from the dealer. I'd suggest
finding another Legacy of similar vintage to borrow from. Perhaps
someone you know has one and would be willing to help out?
Hope this at least gets you started.

ByeBye! S.

Steve Jernigan KG0MB
Laboratory Manager
Microelectronics Research
University of Colorado
(719) 262-3101

 

[Alan]

If you promise not to laugh....

I had a Pacer that had that problem. Okay, it was 30+ years ago, but it
turned out to be a bad wiring harness.

BTW, the Pacer was a great car, small on the outside, big on the inside,
handled and rode like a dream- so stop laughing.

 

[Clifford Heath]

Anyone have problems with their older model (early 90s) Subaru shutting off
at seemingly random occasions?

I had that problem with my Alfa, due to bad wiring between the
battery and the ECU. I'd definitely look at the power circuits.

One thing to check - do the lights go off when the engine stops?

 

[johninKY]

Does the radio stop playing when the engine stalls? Have you checked for
any stored trouble codes? I would think if you lose the radio than the
ignition switch looks pretty good as a possible source of the problem.

 

[Clifford Heath]

...the ignition switch looks pretty good as a possible source of the problem.

In my case it was a dodgey connection to a relay base.
Ignition turned on the relay which fired up the ECU
and fuel pump. Hence my point that you should check
all the main power wiring from the battery to the ECU
as well as the ignition circuit that activates it.