engine hesitation/misfire 2012 LML

maxidale

New member
Jan 3, 2024
1
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1
Perth Western Australia
Requiring help 2012 Chevy Silverado 2500hd was sitting for a while replacing steering box sat for a period of 2 months while sourcing parts and carrying out this exercise. after completing test drive ran out of fuel. refueled and proceeded with test run only to have the exhaust emitting white smoke initially this has since cleared and now engine has hesitation and misfires producing black smoke. (over fueling). This is happening at different rev ranges and sometimes runs fine until it hits third gear. There are no fault codes other than service air bag notice. replaced clock spring corrected service airbag notice but engine fault remained. All boost hoses checked and all found to be in good order. Cleaned and checked MAF and MAP sensors, Turbo has been replaced original appeared to have a lot of wear. The ECM at some point has been tuned. Replaced fuel filter fuel lines have been cleaned and flushed through with F10 cleaner and filled tank. Still no change.
Finding it difficult gaining information on this fault locally here in Australia. Is it time to look at replacing EGR / injectors any ideas or information with this problem would be much appreciated. Regards Rory.