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- 2019 PP1 GT Kona
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- #1
I've been struggling with a low RPM (1500-2100RPM) subtle bucking/shuddering, that felt like an engine miss-fire. Subtle, but annoying as hell as it is most noticeable when just cruising in 5th or 6th. It happens in every gear, but it's really noticeable when you just want to cruise in a relaxed manner.
During free-way cruising, right in the RPM range where the bucking/shuddering would occur, I would get a CEL with engine misfire code(s) that would require a crank-position sensor relearn.
So I dropped the car off at the dealership yesterday. Today the service manager called with what they think is the issue;
Air getting into the intake system past the MAFS.
Some sort of crack in either the intake manifold, or the intake tubing past the MAFS. This would lead to a very lean stoichiometric rate, too much air, not enough fuel. So what I was feeling at low RPMs was knock/detonation??? Basically combustion skipping a cycle?
Head temps did not get high, so I hope I don't have to fear any major damage. The engine pulled strong and clean past 2100RPM.
Now, I would figure the stoichiometric rate was waaay too lean. And of course there were engine miss-fire (random) codes and CELs. Does that mean the engine could tell that detonation was happening due to the mixture being too lean? Or the ECU could tell that normal combustion wasn't happening at the correct time because of the lean condition?
Are these conditions the ECU can detect and then threw misfire codes? For some reason I figured a misfire code meant an electrical gremlin in the ignition system the ECU was detecting.
Also, should I change the plugs?
During free-way cruising, right in the RPM range where the bucking/shuddering would occur, I would get a CEL with engine misfire code(s) that would require a crank-position sensor relearn.
So I dropped the car off at the dealership yesterday. Today the service manager called with what they think is the issue;
Air getting into the intake system past the MAFS.
Some sort of crack in either the intake manifold, or the intake tubing past the MAFS. This would lead to a very lean stoichiometric rate, too much air, not enough fuel. So what I was feeling at low RPMs was knock/detonation??? Basically combustion skipping a cycle?
Head temps did not get high, so I hope I don't have to fear any major damage. The engine pulled strong and clean past 2100RPM.
Now, I would figure the stoichiometric rate was waaay too lean. And of course there were engine miss-fire (random) codes and CELs. Does that mean the engine could tell that detonation was happening due to the mixture being too lean? Or the ECU could tell that normal combustion wasn't happening at the correct time because of the lean condition?
Are these conditions the ECU can detect and then threw misfire codes? For some reason I figured a misfire code meant an electrical gremlin in the ignition system the ECU was detecting.
Also, should I change the plugs?
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