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Engine blow by causing a misfire?

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greddy_1700

15+ Year Contributor
1,037
91
Aug 27, 2006
Regina, SK, Canada
Hey, odd question as I continue to diagnose my engine and its issues, but is it possible for blow by to cause a misfire under boost?

My built 2.3 stroker sat for a number of years before I transplanted it into a new chassis, and it was in great shape prior to removal. Since I have gotten my new 1992 chassis back together and running, my built engine has had awful blow by, where I cannot even complete a boost leak test due to excessive crank case pressure. A leakdown test confirmed that I am pressurizing the crank case through the rings on two cylinders, making me lead towards stuck rings on those cylinders.

This all started when as I was trying to get the car prepped for tuning, I was never able to get the car into boost. The engine runs smooth, idles well, and runs great in vacuum, but as soon as I go positive pressure it just misfires, bucks, and bogs down. Now I have changed out the coils, plugs, wires, transitor, CAS with new, known good units, so I am running out of things that would cause a misfire only under boost. Does it make sense that my blow by would cause the misfire? I dont see anything crazy on my logs to indicate any other issues, the car just falls apart under boost.

Regardless, it looks like I need to tear into the block and re-ring, but just want to see if my thinking is correct and that is likely the source of my misfire. Would hate to get it back together and it still happens, but regardless I know the blow by needs to be fixed.

Thanks!
 
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