1998 manual Subaru Legacy GT stalls at stops and in neutral, and then runs terribly

Discussion in 'Subaru Legacy' started by tragle, Aug 9, 2006.

  1. tragle

    tragle Guest

    Hi,

    Here's the story. I bought a 98 Legacy with only 40K miles, but with
    the "check engine light" on, from a dealer in New Jersey, got on the
    turnpike, and it stalled at the first tollbooth. It started fine, but
    the engine sounded like a lawnmower, was shaking terribly, and had a
    fraction of the power it was supposed to. I brought it back to the
    dealer, he started it up, and it was fine. We later figured out that if
    the car is doing this, you can turn it off, let it sit 5-10 seconds,
    and when you start it up, it's fine.

    Sometimes, the car will start running badly, shaking etc, without
    stalling first. Always, though, it's when the RPMs have gone from high
    to low pretty quickly, like when stopping, or shifting into neutral
    between gears. However, it doesn't always happen, so it's difficult to
    replicate.

    He had me bring it to a mechanic, who replaced injectors and the Idle
    Air Control motor. When I picked it up, the CEL was off, I thought
    everything was okay. First time I get on a highway, though, and slow
    down due to traffic, it stalls, I restart, it sounds terrible and has
    no power, and the CEL is back on.

    The dealer had me bring it to another mechanic, who took out the EGR
    valve and told me to drive it for a week or two. If the car doesn't run
    badly, the EGR was the problem. It ran very good after this for several
    days, but occasionally stalled. Then, one day it stalled and shook and
    had no power. It did this a few times, but not near the frequency it
    had been when I first bought it.

    Then, I took it on a 100-mile trip, and it started stalling almost at
    every stop sign, sometimes running badly afterwards, sometimes not.

    As it is now, I'm taking it back to the second mechanic, who will put
    in a new EGR and then do the "next thing".

    What could possibly be wrong with this otherwise wonderful car?
     
    tragle, Aug 9, 2006
    #1
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  2. tragle

    Jim Stewart Guest

    Find a mechanic that knows how to pull
    the trouble codes from the computer and
    interpret them.
     
    Jim Stewart, Aug 9, 2006
    #2
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  3. tragle

    tragle Guest

    Both mechanics have checked, it's the interpreting that's hard.

    The first one saw a code for the idle air control motor and replaced
    it. That didn't work. The second one supposedly has better diagnostic
    equipment, but there's still the problem of reproducing the problem to
    see what codes are generated.
     
    tragle, Aug 9, 2006
    #3
  4. Idle air control motor? Like the mechanism that opens the air intake?

    I'd suspect the O2 sensor might be bad in that case. See if they can test
    that or replace if it's cheap enough.
     
    Funkadyleik Spynwhanker, Aug 9, 2006
    #4
  5. tragle

    cselby Guest

    Sounds more like an intermittent lose of signal to/from a
    sensor/control unit. You might want to take apart all the
    connectors at the engine and to the ECM, inspect, clean, tighten and
    smear in some dielectric grease. The grease keeps water out of the
    connections and just as importantly, acts as a shock absorber to keep
    the pins tight. Look closely at all the pins. They should all be
    clean and consistantly shiney.

    Pete
     
    cselby, Aug 10, 2006
    #5
  6. Not a bad suggestion, particularly in an older car with a little
    corrosion perhaps. Ground connections are also important.

    As a side note, I just had a MAF behave similarly (intermittent) on my
    daughter's '95 Nissan.

    Is there any corelation with moisture/rain. etc.? Could be a bad coil
    pack or plug wires.


    Carl
     
    Carl 1 Lucky Texan, Aug 10, 2006
    #6
  7. tragle

    tragle Guest

    No -- it's usually been dry when I've driven it.

    I'm going to see if I can get the codes at AutoZone.
     
    tragle, Aug 10, 2006
    #7
  8. tragle

    tragle Guest

    Here are the codes:

    P0400 - EGR Flow Malfunction
    The EGR valve is gone so that makes sense.

    P1101 - Fuel Air Metering
    This is the MAF, I think.

    P1507 - Idle Speed Control
     
    tragle, Aug 12, 2006
    #8
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