P0300
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Today I put back the cleaned injectors from those cylinders...and then swapped them around. I also changed the intake manifold gaskets and checked for any leaks after reassembling. Guess what happened... same misfires on cylinders 2 and 3. The car even better then before which was nice because I cleaned the ports and intake manifold. So only thing left is the computer... but why would it have a misfire only at specific speed and never any other time. Its so strange.
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On The Tree
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Nope runs perfect no lean condition. If it was the whole pump assembly messing up the random misfire would be on more then just cylinders 2 and 3. I learned today though that it occurs when I punch it up to 5k rpm going slow so that means its not just at speed. Now I believe it to be something mechanical. I am lost any input helpful.
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!st thing is pull the plugs and do a compression test on those cylinders. Cracked or broken valve springs, bent push rods, bad lifters. Head gasket blown between those cylinders.......list is endless.
Last edited by TransAmBlue; Jan 25, 2013 at 09:19 PM.
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On The Tree
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Update: Tonight I downloaded a completely stock tune for the 99 and from it I took one of the misfire tables which looked much much different from mine. Copied it into my tune file and the misfires didn't go away but they did switch cylinders!!! Thats good news because it means its not mechanical YEAH. Super excitied that I don't have to tear down the motor. Also the misfires were much fewer in number. So I am trying to figure out all the misfire tables and the healthy stock tune for them since my car is stock (motorwise).
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On The Tree
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Update: Misifire is now cured after draining some oil...it was over filled and changing another O2 which I thought was working perfect but I am unsure now. Not sure what was doing it but thats what I did and bam its gone. Thanks everyone for your input and comments. I hope someone reads this and finds it helpful.
