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Random Multiple Cylinder Misfire - Not Festiva

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  • Random Multiple Cylinder Misfire - Not Festiva

    I really don't know why nothing I touch ever goes smooth.

    00 Honda CRV 2.0

    Came in for a burnt exhaust valve. I changed them all and ground them in. Changed the seals too. Most annoying seal design to get off I've ever seen, BTW.

    Now it idles rough and is misfiring heavily on #3 AND on every cylinder randomly. But then you rev it and it sounds fine. Strong and smooth. Drop back to idle and it goes ape fleas again. Can't hold steady and misfires.

    I've done the following, nothing of which has done anything to stop it.

    1. Swap plug wires, plugs, injector wires, injectors.
    2. Check comp for giggles. It is fine.
    3. Changed plugs for giggles. No change.
    4. Adjusted valve lash. No change.
    5. Checked rotor and button. Looked brand new.

    It's insane. Everything I can physically check seems fine, but something obviously isn't. Any ideas?
    Last edited by sketchman; 10-21-2015, 06:36 AM.
    Any difference that makes no difference is no difference.

    Old Blue- New Tricks
    91 Festiva FSM PDF - Dropbox

  • #2
    Did you check the timing? Sounds like it's firing at the wrong time.
    1988 Ford Festiva "Sonic" BPT g25mr MS2 standalone ecu, FOTY '11, Best Beater FMV, Fan Favorite FMVI

    1989 Ford Mustang GT 5.slow

    1996 Ford F-150

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    • #3
      Ignition? No, and that's a good point. I assumed the dizzy was keyed like a Festiva's, but I didn't actually check it.

      I'll have a look.

      EDIT: Oh, and the reason I didn't check that was because I just put it back the way it was. But I guess it could be off still.
      Last edited by sketchman; 10-21-2015, 07:54 AM.
      Any difference that makes no difference is no difference.

      Old Blue- New Tricks
      91 Festiva FSM PDF - Dropbox

      Comment


      • #4
        Check valve timing again. Make sure marks are dead on. Sounds like its a tooth off.

        Sent from my 7040N using Tapatalk
        Neil

        Jesus loves me. This I know.

        93 L track prep in progress
        88? Parts car-sold
        91 L B6-me f25mr-soon to be ???
        86 b2000- pisses of HOA-sold
        1997 k1500 suburban- kid hauler/GAS hog

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        • #5
          Valve timing is annoying with this. It's a DOHC that rotates CC. There are "Up" marks on the cam gears, and a pointer on the crank gear. Then there are side marks on the cam gears that are supposed to point at each other. Gotta pull the valve cover, belts, etc to do it, but I'll check to see if it needs it.
          Last edited by sketchman; 10-21-2015, 09:19 AM.
          Any difference that makes no difference is no difference.

          Old Blue- New Tricks
          91 Festiva FSM PDF - Dropbox

          Comment


          • #6
            Checked valve and ignition timing. Both are correct, and now it's running so rough I can't even manipulate the idle with the idle screw. AND now it's smoking constantly.

            Yep, time to start selling drugs.
            Any difference that makes no difference is no difference.

            Old Blue- New Tricks
            91 Festiva FSM PDF - Dropbox

            Comment


            • #7
              Those only mask the pain...

              Have you done compression/leakdown test? Running compression test?

              Sent from my 7040N using Tapatalk
              Neil

              Jesus loves me. This I know.

              93 L track prep in progress
              88? Parts car-sold
              91 L B6-me f25mr-soon to be ???
              86 b2000- pisses of HOA-sold
              1997 k1500 suburban- kid hauler/GAS hog

              Comment


              • #8
                I did many static comp tests. Probably 3 now. Leakdown, no. I assume a running comp test is when you let it run on 3 cyls and test one at a time?
                Any difference that makes no difference is no difference.

                Old Blue- New Tricks
                91 Festiva FSM PDF - Dropbox

                Comment


                • #9
                  Yesr, and compare readings.

                  Sent from my 7040N using Tapatalk
                  Neil

                  Jesus loves me. This I know.

                  93 L track prep in progress
                  88? Parts car-sold
                  91 L B6-me f25mr-soon to be ???
                  86 b2000- pisses of HOA-sold
                  1997 k1500 suburban- kid hauler/GAS hog

                  Comment


                  • #10
                    Vacuum leak? Does it have an intake without coolant through it? I had a Ford miss and lope, ended up being collapsed o rings at each port throat. Obviously if there's a leak after all ecm measuring is done, it'll never know to compensate.

                    Might be why it smoked a valve, lean and hot. And now you just upset it to show itself.

                    Or it ran so shittybefore it was hard to determine anyways.
                    Sent from my One using Tapatalk
                    Last edited by jason_; 10-21-2015, 02:55 PM.

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                    • #11
                      I've checked a lot for leaks, but that's still possible I guess.

                      Just did the running comp. Worst cyl is 40psi lower than plain comp test. Best is 10psi below.

                      Should mention I also already adjusted the valve lash. That didn't do anything either.
                      Any difference that makes no difference is no difference.

                      Old Blue- New Tricks
                      91 Festiva FSM PDF - Dropbox

                      Comment


                      • #12
                        Look into the intake valve on that cyl that is low

                        Sent from my 7040N using Tapatalk
                        Neil

                        Jesus loves me. This I know.

                        93 L track prep in progress
                        88? Parts car-sold
                        91 L B6-me f25mr-soon to be ???
                        86 b2000- pisses of HOA-sold
                        1997 k1500 suburban- kid hauler/GAS hog

                        Comment


                        • #13
                          You thinking it's blocked or not seating? I can't really look in it without pulling the IM off.
                          Any difference that makes no difference is no difference.

                          Old Blue- New Tricks
                          91 Festiva FSM PDF - Dropbox

                          Comment


                          • #14
                            I think its to tight keeping it slightly open.

                            Sent from my 7040N using Tapatalk
                            Neil

                            Jesus loves me. This I know.

                            93 L track prep in progress
                            88? Parts car-sold
                            91 L B6-me f25mr-soon to be ???
                            86 b2000- pisses of HOA-sold
                            1997 k1500 suburban- kid hauler/GAS hog

                            Comment


                            • #15
                              Ahh, that I can check.
                              Any difference that makes no difference is no difference.

                              Old Blue- New Tricks
                              91 Festiva FSM PDF - Dropbox

                              Comment

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