Before I go into a much longer and detailed post about what I think is a problem (though probably a minor problem), I want to get an opinion on if this is normal or not. I'm assuming it's not normal, but I don't spend a lot of time around other people's M20B25s. I'm not so much looking for a solution in this thread, as I am a few people saying "Yep, that's a problem" followed by "that's classic misfiring" or "That is likely something unrelated to fuel and spark".
In case it's hard to tell, the change in sound and what sounds like the engine lagging for a split second is not rhythmic. With poly engine bushings, I can feel it in my seat almost more than I can hear it from inside the car.
From the tale pipe. This ended up being more muted than I thought it would be, but besides the sound, it also exhibits a sort of puffing sound. If you were to measure the velocity of the exhaust gasses, I'm positive they would read differently around the time the engines misses.
From inside. Notice how spot on the needle is. You can see a slight quiver between 15s and 18s. The needle only moves when a few of the misses line up back to back.
Finally, here it is off of idle. The same thing happens, just with more frequency. Outside of the obvious change in the primary sound, you can hear little popping sounds that were rather muted by the mic. Also take note that in this one the camera is setting on the coolant reservoir and any shaking in the camera corresponds perfectly to the engine misbehaving.
One last thing. When reviewing this video I noticed a sound that seems unrelated but shows up at about 25s and goes in and out through the end of the clip.
In case it's hard to tell, the change in sound and what sounds like the engine lagging for a split second is not rhythmic. With poly engine bushings, I can feel it in my seat almost more than I can hear it from inside the car.
From the tale pipe. This ended up being more muted than I thought it would be, but besides the sound, it also exhibits a sort of puffing sound. If you were to measure the velocity of the exhaust gasses, I'm positive they would read differently around the time the engines misses.
From inside. Notice how spot on the needle is. You can see a slight quiver between 15s and 18s. The needle only moves when a few of the misses line up back to back.
Finally, here it is off of idle. The same thing happens, just with more frequency. Outside of the obvious change in the primary sound, you can hear little popping sounds that were rather muted by the mic. Also take note that in this one the camera is setting on the coolant reservoir and any shaking in the camera corresponds perfectly to the engine misbehaving.
One last thing. When reviewing this video I noticed a sound that seems unrelated but shows up at about 25s and goes in and out through the end of the clip.
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