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2013 Silverado 5.3 cylinders 1&2 misfire at idle flex fuel
Cylinders 1&2 misfire at idle / low rpm misfires less or not at all around 1500-1800 rpm.
swapped injectors , coils , plugs and wires.
St fuel trim 7-9 Lt fuel trim 18-19 both banks.
P0172 & P0175 P219 A and B codes are permanent
No misfire codes.
Alcohol content 1%
High fuel trims on both banks... Do the trims improve off idle? Or as the engine warms up?
If they do improve, smoke the intake for a leak. If they don't improve, look towards a lack of fuel delivery. Dirty MAF, fuel pressure, like that.
Speaking of fuel, has anyone taken a fuel sample yet? I'd be interested to know if there's E85 in the tank, or some mixture of E85/E15. I know the ethanol content is shown at 1%, but that doesn't make it true. P0172/P0175 suggests someone was fighting an ethanol issue at some point.
Fuel trims stay the same after engine hits run temp. Should have mentioned that I did smoke test entire system is tight. Swaped out MAF sensor with several including brand new OEM. Fuel pressure checks out fine. Never used E85/E15. I’m the only owner and never fought this problem before. I should also mention that this is an AFM engine. Thanks again Sarge
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