Announcement

Collapse
No announcement yet.

severe missfire problem

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Question : severe missfire problem

    i have a 1995 olds ceira wagon with he OBD1 that was half OBD2,the problem i am having is it acts like its not getting fuel or spark when its under demand of acceleration.

    the following parts have been replaced this month and show no signs of helping
    fuel pump and sending unit
    spark plugs and wires,coil packs and the computer that sits under them
    fuel filter
    cleaned mass airflow sensor

    if the throttle pos. sensor is unplugged it will run a little better but still stumbles,misses real bad.when TPS is plugged in it runs much worse and i never get a code from any of this. what could be causing this?

    also note car will start and idle fine.

  • #2
    Test the cat converter. In bolt the O2 sensor at the rear exhaust manifold or egr pipe.
    88 Beretta GTU turbo . 90 Black ASC/McLaren TGP, awaiting 4t80. 2003 Grand AM se 3400/4t45 daily grind.

    Comment


    • #3
      that got replaced with a resonator 40K ago,check eng light finally came on.i had to get to my sisters as fast as i could,i locked her in second and wide open i went....dumped it in 3rd at 120 mph and the check engine light came on,ill get it scanned tomorrow and see what triggered it.(it took forever to get that fast but it did it!)

      Comment


      • #4
        120 MPH? hmmm fuelcut anyone???
        "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

        Comment


        • #5
          Haha yeah sounds like factory fuel cut.
          '89 Firebird, 3500 Turbo, T56, 9-bolt/4.11
          '86 Fiero, 3500, 4-speed

          Comment


          • #6
            Originally posted by caffeine View Post
            Haha yeah sounds like factory fuel cut.
            hmm....ive had this thing faster then that.but i think i know the code ive gotten,i think its because i have a coil pack failing,it only does it as soon as it warms up.i think the TPS sensor may have a good role in it too since it got hung up today and made the engine race.

            Comment


            • #7
              not trying to be an asshole here, but 120 MPH in second gear?



              it's not happening in a sierra wagon that doesn't have a hell of alot done to it, and if it's obd1.5, it won't have much done to it as the tuning software and know how isn't there like obd1 or obd2. I have no problem trying to help, but please, no BS.


              start with the TPS, put an ohm meter on it and measure the resistance, it should smoothly raise and lower, if it jumps. it's bad.

              the ICM is very possible, they typically fail hot rather then cold, but the DIS ICMS are also pretty robust compared to the ICMs in the distributors. a failing coil will affect 2 cylinders, not just one, and probably keep the car from running at all.

              Might also want to check all of the grounds, including the ground cable from the battery.
              "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

              Comment


              • #8
                hmm...i think ill have to make a vid of this,but i will do that and let you know.today im supposed to take it in and see what the check engine lights all about.have you ever heard of a car running like this because of the transmission? i had a 95 and a 98 buick that would do the same,only they would get so bad they would die and there you sat for an hour
                .

                Comment


                • #9
                  replaced the TPS today,that seemed to of helped some but the miss is still there.looks like im going to have to rip the plenum off and check the injectors.

                  Comment

                  Working...
                  X