99 Sonata Hard Start Problem

Discussion in 'Hyundai Sonata' started by 99trooper, Sep 14, 2005.

  1. 99trooper

    99trooper Guest

    Hello again,

    My 99 Sonata (2.5 V6) has a problem... It is taking way to long to start
    it....It cranks normally but it takes a good 5-10 seconds to start. Once
    it starts, it runs fine (no stumbling, etc...)

    I checked the fuel supply at the return on the regulator (took off the
    return line, and cranked a little, and gas came out of the rail through
    the regulator... So I guess I'm getting gas.

    When I bought the car, the dealer told me they had to replace some things
    before they sold it to me 3/05 and I think he said he replaced the plugs &

    I pulled the front 3 plugs to examine (By the way, I have good spark thru
    the wires) The plugs look as though they have 50k miles on them (Champion
    plugs). The plugs were black, and had carbon build-up on the ends of the
    plugs, also carbon/oil buildup around the threads. The wires looked ok,
    but not like they had only 6k miles on them (That's how much I put on
    since buying it in March)

    The car acts like it is flooding, why isn't it firing?... If I push the
    gas pedal all the way down while starting, it seems to help start

    What else can I check out? Air filter is clean...PCV valve may be? Also
    the oil cap closes, but has up, and down loose movement. Should I change
    the plugs and wires first?

    99trooper, Sep 14, 2005
  2. 99trooper

    hyundaitech Guest

    I think you misunderstood the type of problem the regulator has. The only
    way to test well is to attach a fuel pressure gauge.

    If a regulator causes the problem you're having, what typically happens is
    that the regulator gradually bleeds off the fuel pressure back into the
    tank while the car is off. Then it takes the fuel pump a while to build
    the pressure back up.

    On most cars, the regulator will hold 20 to 30 psi fuel pressure while the
    car is off, even overnight.

    The fact that fuel came out indicates that your fuel pump is operating
    (although we still don't know if it can deliver the proper pressure and
    volume) and that your regulator is bleeding excess back to the tank while
    the pump is running. But it doesn't indicate the regulator is not
    bleeding down as the car sits unused.
    hyundaitech, Sep 14, 2005
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