Announcement

Collapse
No announcement yet.

M42 problems, help.

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

    M42 problems, help.

    Long story short, someone poured bleach in my gas tank. I didn't know know that it happened so i started the car and it died after about 20 seconds of running. Noticed my gas door was pried open, bleach all over the floor next to it, and the cap to the bleach bottle. I drained the tank, replaced the fuel filter, "upgraded" the injectors to 4 pintile mustang injectors with the same flow rate, replaced the fuel pump to a off brand walbro 255, put fresh gas in, and replaced the spark plugs. Starts but runs horrible. Only stays running with throttle input. Sounds like it's running on less than 4 cylinders. It's also backfiring from what seems to be right under the intake manifold, like an actual pop and flame, something i'v never seen before. I was guessing maybe the timing chain skipped a tooth and now the timing is off, resulting in a backfire, but i checked the compression and it's good and even for every cylinder. I'll take as much help as I can get, i'm very stumped. Thanks!
    Stomp test shows code 1215.

    #2
    Maybe the bleach ate a hole in the lower intake manifold to head gaskets?

    Comment


      #3
      I wonder if the FPR is the issue here. If the diaphragm failed you might experience such an issue. For those first 20 seconds how was the car running?

      Comment


        #4
        Double check that your spark plug wires are ordered correctly. As for the flames, you need to check and make sure all hoses and gaskets are intact in the intake manifold.

        As for Code 1215:
        This code is stored if there is a break or short-circuit at: Air Mass Flow Meter or its supply wires or the voltage supply to Air Mass Flow Meter insufficient. Cable damage is the most common cause of this trouble code.

        I'd check the other stuff first, then clean the AFM connectors and inspect it to make sure the flap is swinging freely.

        IG @turbovarg
        '91 318is, M20 turbo
        [CoTM: 4-18]
        '94 525iT slicktop, M50B30 + S362SX-E, 600WHP DD or bust
        - updated 1-26

        Comment


          #5
          Originally posted by roguetoaster View Post
          I wonder if the FPR is the issue here. If the diaphragm failed you might experience such an issue. For those first 20 seconds how was the car running?
          Was running perfectly, didn't even suspect anything being wrong.

          Comment


            #6
            I think it's safe to say that whatever the case you'll need to strip the intake down again and double check that everything is seated/flush/intact.

            Comment


              #7
              What a total asshole who did that to you. That is why I have a dashcam on both side of the car.

              Comment


                #8
                Sad that this happened in Walnut Creek! Good luck getting this figured out.

                OBDI M62B44/6 swap
                Transaction feedback
                - jpod999

                Comment


                  #9
                  So i replaced the upper intake manifold gasket and the backfiring stopped and the motor idles now. it's running very rough though. stomp test now shows code 1222. im guessing maybe o2 sensor might have gone bad from running the motor so many times while diagnosing. also the pcv hose going from the valve cover to the throttle body ripped so i just plugged both sides, would that be the the reason it would run rough?

                  Comment


                    #10
                    Did you take the lower intake manifold off as well to double check the gasket?

                    O2 sensor should not go bad from idling unless it was already faulty.

                    You need to reinstate the vac hose that you capped. If it's the one from the front of the VC to the TB you need to reinstate it now as that's the exit for PCV gasses, which are essential to evacuate from the engine. Do it ASAP, before driving the car if possible, if not, remove the plugs to drive to the store, even though this will cause it to idle poorly.

                    Comment


                      #11
                      Originally posted by roguetoaster View Post
                      Did you take the lower intake manifold off as well to double check the gasket?

                      O2 sensor should not go bad from idling unless it was already faulty.

                      You need to reinstate the vac hose that you capped. If it's the one from the front of the VC to the TB you need to reinstate it now as that's the exit for PCV gasses, which are essential to evacuate from the engine. Do it ASAP, before driving the car if possible, if not, remove the plugs to drive to the store, even though this will cause it to idle poorly.
                      I didnt even remove the lower intake gasket cause it was running perfectly before the bleach so im sure it's fine. the upper was bad from removing it to many times and ripping it. the upper manifold also wasnt seated correctly as well.

                      Do you think the pcv hose would be the root of the rough idle? it starts right up but vibrates the whole car and sounds like a harley from the tailpipe. it smooths out after 2k but revs much slower up to redline than it used to. iv replaced everything the bleach could have affected so im just lost at this point.

                      The reason i think it may be the o2 sensor is because the car was blowing smoke out the tailpipe before and i ran it for a while like that so i think that it might have fouled it.

                      Thanks for the help, i really appreciate it.

                      Comment


                        #12
                        Oh, I thought you meant the O2 might have died from post bleach removal running. Since you haven't replaced it it may be worthwhile. AFAIK chlorine is an oxidizer, although I am not sure if the reaction that would take place when mixed with gasoline would be harmful to the lambda sensor.

                        In any case I'd start with the hose as leaving it open is a massive vac leak, and capping it raises internal case pressure. Both of which can cause operating issues.

                        Comment


                          #13
                          Originally posted by roguetoaster View Post
                          Oh, I thought you meant the O2 might have died from post bleach removal running. Since you haven't replaced it it may be worthwhile. AFAIK chlorine is an oxidizer, although I am not sure if the reaction that would take place when mixed with gasoline would be harmful to the lambda sensor.

                          In any case I'd start with the hose as leaving it open is a massive vac leak, and capping it raises internal case pressure. Both of which can cause operating issues.
                          got a new temporary hose and it's all sealed up now. still the same. checked the plug wires to see if they all arc when taken of and they do, but when i remove cylinder 1 and 4 the car still runs the same. could the injectors be bad even though they were tested before i bought them?

                          edit: wires are fine, checked with another set. Injectors are fine, checked the resistance and they're spot on.
                          Last edited by redreda1313; 04-11-2016, 06:43 PM. Reason: update

                          Comment


                            #14
                            If you removed 2 wires and the car still runs the same you have switched wires, dead coils, or bad coil drivers in the DME. Obviously, I'd start with switching plug wires around.

                            It's possible that the injectors are bad, but I'd doubt it. However, if you haven't replaced the FPR or rail there could have been some rust that happened within the system as that's what chlorine is supposed to do.

                            Comment


                              #15
                              Originally posted by roguetoaster View Post
                              If you removed 2 wires and the car still runs the same you have switched wires, dead coils, or bad coil drivers in the DME. Obviously, I'd start with switching plug wires around.

                              It's possible that the injectors are bad, but I'd doubt it. However, if you haven't replaced the FPR or rail there could have been some rust that happened within the system as that's what chlorine is supposed to do.
                              pulled the plug wires going to the plug on 1 and 4 and put a plug in them. they spark fine. spark is fine, which leads me to believe that the fuel is the problem and not spark. Injectors are fine. replacing the fuel rail and fpr next. anything else i should do?

                              Comment

                              Working...
                              X