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Misfire code cylinder 8

huntiez

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is your manny locked out or imrc active cause if their active isit their a issue with boost forcing them open which could cause a miss fire
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Gearhead82

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they did a compression test on cylinder 8, it was like 100% comparied to cylinder 7 that read 200% .
What does this mean? Do you mean 100psi and 200psi? If you have low compression on one cylinder then stop messing around with anything injector or ignition related and fix the mechanical issue first (ring/piston or valvetrain related most likely).
 

ahl395

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Are they locked out with the MMR pieces or just left disconnected or with zip ties? if not the MMR piece maybe one of the flaps failed and flipped down.

What are the actual compression readings in psi.

Have them also check the spark plug gap. Even if the plug is ok if the gap is huge it can cause misfires. Regap plugs and swap into difference cylinders, swap coils around cylinders.

If your Cyl 8 compression is half of cylinder 7 the rings or valves are done, leakdown test needed.
 

Grimace427

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Does that mean my injectors are working properly?
Not enough information for that, but as far as your fuel trims at idle those look fine. A small variation between banks is normal. If the difference was larger there would be an issue but also a CEL for a/f mixture imbalance.
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