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I have a 95 subaru 2.2.  Three times in the last month, the car has died while running at 30-60 mph.  It happens relatively fast but I can baby it for a mile or so at low speeds.  At this point, the battery is dead.  The last time, I pulled the alternator and had it tested by Advanced Auto and Napa.  Advanced auto said it was bad and Napa said it was good.  Go figure.  Hopeing that AA was right, I swapped alternators from a U-pull-it. 

 

After swapping the alternator, I jumped it, it started fine, and it ran OK for a week.  But the problem has reaccured.  I'm thinking that there must be a intermittent short either between the alternator and battery or on the discharge of the battery.  Is there a regulator between the alternator and the battery that could be a problem?

 

Any ideas?

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I guess I have to remove bundle cover on the wiring connecting to the alternator and inspect the wiring.  It could be a brittle connection.

 

I gather form searching that there is no independent voltage regulator.  But does the wire from the altenator go directly to the battery?  It doesn't look like it but that could be the way the wires are bundled. 

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Wire from the alternator leads to the fuse box where the connection is made to another cable that leads to the battery.

 

So when the engine stalls it has to be jumped? Alternator has been replaced. Have you cleaned the terminals on the battery?

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I'm sorry to say that I didn't clean the battery terminals.  The battery was dead after I limped into a parking lot.  When I swapped the alternator, and then jumped the battery for 30 sec, the car started and ran fine for a week.  I thought Problem Solved! 

 

Obviously, I didn't need to swap the alternator.  Maybe something I did when I swapped it temporately fixed the problem or maybe it just randomly fixed itself when the engine cooled down?  Strange.  Unfortunately, the car is now 70 miles away and I have a logistic problem getting it back here to work on.

 

I suppose that the alternaor needs to ground itself though the bolt that it pivits on and that might be the answer.

 

Why does the power wire from the alternator to the battery go through the fuse box?  Is there a fuse on it?

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Try replacing the battery terminals. Maybe one is loose. I like to use the brass marine terminals with the wing nut for replacements.

 

the alternator wire goes to the fuse box as fara s joining the rest of the harness, but schematically, it goes directly to the battery. If you suspect this cable is shot, you can try jumpering the terminal on the alt to the battery with a jumper cable and see if she pulls a charge.

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A bad alternator can kill a good battery.

 

Alternatively, a bad battery can kill an alternator.

 

The two ARE related.

 

Yes, check your wiring for brittleness, corrosion, bad connections that can lead to early failure, but you really do need a fully charged battery (minimum of 11.5 volts) and a good alternator for the system to work properly.

 

Hooking a bad/dead battery up to a good alternator can cause premature failure by making the alternator work overtime trying to recharge the bad/dead battery as well as trying to run/keep up with the electrical system requirements of the running car. These are fairly small alternators - they dont particularly like being overworked.

 

The battery is used primarily for starting purposes. Once the car is running, pretty much all of the electrical power to run the car, and it's accessories (lights, wipers, radio, etc), is supplied by the alternator.

 

So again, I reiterate, do not rely on the alternator to recharge a dead battery.

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  • 2 weeks later...

UPDATE

 

The car is still stalling and I'm $500 poorer. 

 

To reiterate, the car is stalling randomly about every 2 weeks.  The car runs OK for a number of days, but then after starting and running for 5-20 min it loses power and then eventially stalls completely.  Contrary to what I first reported the battery is OK.  No doubt the original alternator was OK too.  Apparently, after sitting for a while, the car will run normally, again for a number of days.  This fooled me thinking that I solved the problem when I replaced the alternator.

 

When the car was 75 mi away from home last week, it stalled again.  The battery still had 12.6 volt on it.  Diagnosis by a shop said it was a failing fuel pump.   This wasn't a really bad diagnosis, but the car stalled again yesterday after they replaced the fuel pump.  This time I had it flat bedded back to my house.  I think the shop was half right, but the problem is the electrical to the fuel pump, not the fuel pump.

 

Now that it has sat overnight in my driveway, it runs fine.  I looked at the wiring to the fuel pump.  It looks OK, including the plug under the back seat.  I'm thinking the problem might be the pump relay, which I have located.  The only other possibilities is the wiring from the relay to the pump or the plug at the pump.

 

I have to have to start guessing and replacing parts.  Any other ideas?

 

 

 

 

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Fuel pump is electrically powered. Relay needs power too. Alternator diodes frequently fail intermittantly due to heat.

 

yes, they do, but they typically cause the dash lights to at least flicker when the problem starts to arise - recently had that issue with a so called "lifetime warranty" rebuilt alt from a chain parts store - and of course it would never act up when I took it in to be tested - I dont think that is the problem here...

 

from reading the OP's posts, there is apparently no warning when the car stalls - or very little warning...

 

to the OP - Relays are not that expensive, so replacing that item wont break you...

 

if/when this happens again, I would suggest doing a couple of "diagnostic" type tests right away - keep a set of basic tools in the car - sockets/ratchet (including a spark plug socket), phillips screwdriver, pliers, a cheap pair of plastic tongs and an empty bottle of some sort - soda, windshield washer fluid, etc...

 

1. make sure there is spark - pull a spark plug, plug it back into the plug wire, and using the plastic tongs, hold it close to a strut bolt, or something similar - crank the engine & make sure there is a good strong spark...(using the tongs prevents you from getting a jolt - and it DOES hurt!)

 

2. check to make sure fuel is gettting to the engine - pull the main fuel feed off the engine side (the one that comes off the fuel filter), stick the end in the empty bottle, and crank the engine breifly - does fuel come out?

 

Speaking of fuel, when is the last time the fuel filter was changed? another fairly cheap item...

 

If either of the above are missing, or weak, when the car stalls out - you will know where to investigate further.

 

 

When this happens, how long have/had you been driving the car for that particular drive? (as in from the time you turn the key until it stalls out)

Does it happen after only a few minutes?

Or does it seem to be a longer period of driving before it stalls?

or completely random? (sometimes a long period, sometimes short?

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Thanks for the suggestions.  I will definitely be prepared to do more diagnostic tests when/if it stalls again.  I did change the fuel pump relay.  It was, by the way, was very difficult to reach.

 

In one case, the car stalled about 30 min after starting.  It had run OK for 100 mi over 7 days.  It stalled at 70 mph.

 

Another time, it stalled about 5 min after starting. It had run OK for a couple of days.  It stalled at 45 mph.

 

Since I swapped the alternator and since there is no dashborard electrical indication before stalling, it would seem unlikely that it is an alternator issue.  It doesn't set a check engine light.  I forgot to mention, that the fuel filter was changed at the same time as the fuel pump.  It's a difficult problem.  I keep making changes after it stalls and I've been fooled into thinking that the change solved the problem. I will certainly update in a weeks time or sooner if it stalls. 

 

 

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It just stalled again!  At least the interval between stalling are getting shorter.  I only drove it 10 miles since the last stall.

 

This time I was ready and set up a voltage indicator on the wire to the fuel pump.  I could clearly see that the engine was starting to miss before the voltage to the pump droped to zero!  They are close to simultanious so it's easy to make a mistake.  This is the mistake the shop made, I think.

 

So first I changed the coil, no improvement, still stalling.  Then I changed the igniter, and the car started to run OK.  At least I could drive it back 3 miles to my home!

 

This time it did set a check engine light but I'm too afraid to get on the highway to get to a place to check it.   I will update later.

 

 

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I keep making changes after it stalls and I've been fooled into thinking that the change solved the problem.

 

 

the fuel pump pressure dropped to zero so you replaced the coil and igniter? 

 

i don't know the connection between fuel pump pressure and coil and igniter?

 

You are making illogical changes without knowing enough specifics. Changing stuff randomly does not really help and ends up just frustrating everyone.

 

you need to find out what the code is that is causing the CEL - that will point you in a better direction. Pretty much any chain parts store should be able to read the codes for you (Advance, O'rielly, AutoZone, etc), or borrow one if you know someone that has OBD-II reader (maybe ask about possibly renting one at one of the chain parts stores?)

 

just as an FYI - we picked up a used Actron brand reader at a pawn shop for about $35 - works great...

 

In the mean time - some reading material for you...

 

http://jdmfsm.info/Auto/Japan/Subaru/Legacy%20Outback/1995/Service%20Manual/TROUBLESHOOTING%20SECTION/ON-BOARD%20DIAGNOSTICS%20II%20SYSTEM/MSA5TCD95L5876.pdf'>general diagnostics table

 

Specifically Item #5 on that first table (the next few pages are for tranny problems), note the possible causes...

 

Then, take a look at this - MAF code info

 

scroll down to the 3rd page - Note the symptoms of a problematic MAF - sound familiar?

 

Complete trouble shooting section for 95 Legacy/Outback

 

The above is a huge file, but has GOBS of troubleshooting info in it...

 

or, for smaller files, faster loading, try here - same info, just broken down into smaller, logical sections for faster loading times

 

Get that code read - somehow, someway...

 

 

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Car stalled again.  This time it only went 1 mile.  I have no other choice but to guess and I'm only using u-pull-it parts.

 

Grosegary:  The diagnosis of a fuel problem was made by a shop 75 mi from home.  I felt like I had no choice but to try it.  It's apparent that the shop didn't consider/rule out a simultaneous electrical failure.  So they saw the fuel pressure drop and concluded it to be a fuel pressure problem without considering that the voltage to the pump was cut off.  But, since the pump, filter, and relay are new, and I can see the voltage to the pump is OK in real time, then I now conclude that there is and was no fuel problem.  I spent $500 for nothing.  Actually it's worse the nothing, it was for inferior parts.

 

So, on the electrical, I've replaced the igniter, coil, wires and plugs.  It still stalls.

 

Most of the time there has been no codes.  However, after the shop replaced the fuel pump, the car almost immediately showed a MAF failure code after we drove off.   I figured that the shop had forgot to plug in in the MAF and the code reflected that.  The car ran fine for 30 miles.  But maybe that was sign.

 

I can't get to Advanced Auto to read the current code!  I was just on the way there when it stalled.  I'm going to follow up on Ivan's suggestion on the connections and grounds especially under the fuse/relay box.  I may get another MAF and plug it in [for $10].  If it can get to  run for 2 miles, I'll have the code read.

 

Thanks for the ideas.  This is an odd problem.

 

 

 

 

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I'm guessing you've re-tested your alternator... I had to replace the wrecking yard one for it's defect & the next one they gave me was also a problem... re-manufactured from Subaru dealer was like $80 & has kept the charge up & stalling out down (none)

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UPDATE

 

Problem solved.  I finally got to advanced Auto to read the code.  The code was MAF failure [P0100].  So I went to u-pull-it and got a replacement MAF [$25].  Since then I have driven 70 miles without a problem so I'm relatively sure that the problem is solved.

 

Credit where credit is due:

 

Ivans suggestion that the frame ground at the battery should be checked was a good one.  The ground didn't look good at all.  It might have been part of the problem.

 

Heartless suggestion to look at the General Diagnostics Table was a good one.  The table only has 6 reasons why a car would stall, one of which is a MAF failure.

 

Finally, under lessons learned, it is always dangerous to take the car to a shop if you arn't relatively sure of the problem.  The shop's diagnosis is often wrong especially when there is no code and, not only is the fix expensive, it leads one down the wrong path to correct the problem.  This is the second time I got fooled by a shop diagnosis.  What I should have done, is flatbed the car to my home and worked on it for a few days to figure out the problem even though the tow cost would have been $250.

 

 

 

 

 

 

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:clap:  hopefully the problem really is solved for you!

 

But yeah, just throwing parts at it when you really dont know what the real problem is/was does nothing but lighten the wallet...

 

I had one once that took several days to figure out with near constant emails back and forth with a member - We did finally figure it out, but dang it was frustrating!

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I had this cutting out problem for first time last night. Have had this Legacy for 18 months and this is the first problem I have had with it. This morning I will try to see, following your helpful posts. If I find out anything I'll post here.

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