1988 Plymouth Reliant station wagon fuel pump failure

Discussion in 'General Motoring' started by William R. Walsh, May 11, 2009.

  1. Hello all...

    I recently traded a 1990 Chevy Lumina for a 1988 Plymouth Reliant
    wagon with the 2.5L four cylinder engine. (As far as I'm concerned, it
    was a good trade. The Lumina needed a starter and the Reliant needed
    some tune-up on the ignition. Both cars are in decent shape. I had a
    1984 Reliant that I really liked--it ran well, looked decent and drove
    nicely but rust ate the underbody. This wagon is dusty but sound.)

    Anyway, the Reliant ran and drove perfectly until I learned that the
    gas gauge is not especially accurate at the low end of the gauge (it
    read slightly over 1/4 tank) by running it out of gas while driving it
    around the yard. I put more gas in (six gallons) and it started right
    up. I drove it some more, parked it and when I went back, the fuel
    pump was dead silent. It had been making a soft hiss while operating.

    I checked the wiring and the relay, but both of them are good and
    there is power leaving the relay for a short period after the key is
    turned on. So I guess the pump was on its last leg and that I just
    happened to push it a little too far.

    I'd like to replace it, but I'm not sure what is involved. Does the
    tank have to be dropped, or is there any hope of finding an access
    door leading to the top of the tank in this car? The tank is right
    under the rear seat, and looking under the cushion revealed insulation
    that appears to be firmly glued in place. How long should a job like
    this take, assuming one were to get the car up on stands and work in
    the driveway?

    Finally, are there any "gotchas" or things to be particularly aware of
    while doing this?

    Thanks in advance for any advice, hints, tips, etc. All will be

    William R. Walsh, May 11, 2009
  2. Perhaps I should have first replaced the battery. The one that came with it
    was very bad. Everything electrical was struggling a bit, and the alternator
    exhibited very unstable regulation at times.

    Swapping a good battery into place brought it back to life, caused it to run
    better and made the "check engine" light go off and stay off immediately.
    (Checking the codes gave a "12" and a "55", which seems to be the expected

    William R. Walsh, May 12, 2009
  3. William R. Walsh

    Bill Putney Guest

    The thing about the fuel pump only running briefly when you truned th
    key on would be normal for many cars - the pump runs on a timer for a
    second or so to make sure the fuel rail is full and pressurized for
    starting, then the pump will be turned on full time after the computer
    detects that the engine is actually running. I assume the Reliant is
    that way - could be wrong.

    The alternator not regulating well while the battery was failing is not
    uncommon. A common failure mode on batteries is that they develop
    internal intermittent shorts in one or more cells - shorts being periods
    of high current draw (beyond the capability of the alternator to
    maintain voltage, thus fluctuation in the regulation).
    Bill Putney, May 12, 2009
  4. Hi!
    It appears to function in the manner described. Upon turning the key
    on, there is a brief soft buzz from the fuel tank.
    Even when unloaded the best the battery could manage was 11.1 volts.
    Turn the key on, and what voltage there was disappeared. I should have
    just replaced it, instead of messing around.

    I'd started the car a few times by jumping it with the other Reliant.
    Finally, I pulled the good battery and put it in this car. Night and
    day difference.

    The thermostat was changed recently on this car--is there anything
    special about doing this? I saw some references to a special coolant
    fill procedure in the group FAQ that was posted the other day. It was
    not completely clear if it applied to this vehicle or not, but I would
    not like to damage the engine.

    William R. Walsh, May 12, 2009
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