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Message: <blockquote data-quote="TechJ831" data-source="post: 17320" data-attributes="member: 5720"><p>Unfortunately this is a common issue with this engine, not sure what Chevy was thinking but the previous version of it was just as bad, the reason the HPFP ( high pressure fuel pump ) can go is once these things have the PCV clogged up and the rear main is leaking, this normally is followed by a timing issue, there is a certain guide in the timing system that breaks or moves and stretches the chain, I say this because the cam shaft and it’s end lobe is responsible for the HPFP, if the vehicle timing is retard or advanced it will cause the HPFP to run rough, we have come across multiple with this exact issue. The first one we cleaned the PCV system/orafices ( there was zero codes for the timing or HPFP ) finish the cleaning and it still runs bad but now throws a code for the HPFP, it’s keeping PSI, has voltage on sensor. But we end up scoping the timing and comparing it against a known good and see the timing is off. So we did a timing job and replaced the HPFP’s pressure line and the thing ran perfect. What I will say about the timing of them saying it had to be replaced is. To do the PCV job you have to remove the HPFP. So either it was out of timing ( without them knowing because there was no code ) and caused a failure in the pump, or it was bad the entire time but with the reduced power engaged there’s no way to tell</p></blockquote><p></p>