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Misfires on all cylinders no check engine light

Old 02-12-2019, 12:52 PM
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Default Misfires on all cylinders no check engine light

I have a 2006 impala ss 5.3 ls4, it bucks and surges under light acceleration when the converter is locked. Not getting any codes but it shows all cylinders are missing randomly on my scanner. It runs fine wide open or if you get in it hard enough to make it downshift. Its stock other than a cai,and cat delete with dod tuned out. Ive replaced the plugs and wires and no difference. Anybody got a idea what it could be.
Old 02-12-2019, 01:20 PM
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When DOD was tuned out, what else was done to the tune?
Old 02-12-2019, 01:24 PM
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Originally Posted by G Atsma
When DOD was tuned out, what else was done to the tune?
It has a custom tune from diablew on it thats been on it 4 years ive flashed stock tune back no change.
Old 02-13-2019, 05:05 PM
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The 4T65E transmission in these cars is notorious for converter issues and other issues. It sounds like the converter clutch or the valve body solenoid for the TC clutch is failing. There is a valve in the valve body that starts to wear and causes issues or if the car had DOD for some time the DOD function in the motor causes the converter clutch to wear down to bare metal. This causes surging, shudders, cruising rpm instability which can cause misfires.
Old 02-13-2019, 06:34 PM
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Originally Posted by HighAltitude
The 4T65E transmission in these cars is notorious for converter issues and other issues. It sounds like the converter clutch or the valve body solenoid for the TC clutch is failing. There is a valve in the valve body that starts to wear and causes issues or if the car had DOD for some time the DOD function in the motor causes the converter clutch to wear down to bare metal. This causes surging, shudders, cruising rpm instability which can cause misfires.
Trans was rebuilt 5k miles ago with a new converter. I went straight to my trans guy when it started and they say there is nothing wrong with the trans its the engine. Ive been messing with it for almost 2 months and cant come up with anything.


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