Knock at low rpm

[sawmilldmax]

My LB7 daily has developed a knock at idle and low rpm. I checked the balance rates with my v2 and one was 1.2 in gear and warm with the rest below one. The old girl has 376000 plus on her and over 200000 on the injectors. It has an Airdog 150 I installed with the injectors and run additive and trans fluid in the fuel regularly. I put an FPR on about 100000 ago, but the actual rail pressure is 18537 at idle and desired is 18543 psi. It also lopes sometimes when you coast to a stop.The truck is bone stock. That cp3 is bound to be tired but I'm guessing an FPR failure, and I do mean guessing. Any help would be greatly appreciated. Thanks.

 

[Chevy1925]

desired should be 5k at idle, not 18k. id start looking into why desired is wanting to be so high. broke wire, bad connection, ecm/tune commanding it for some reaon, etc.

Dont condemn the FPR till you find out why something is commanding it to be so high.

your balance rates will be far off till the rail pressure is corrected

 

[sawmilldmax]

I talked to a friend today and he led me, I hope, in the right direction. I thought the rail was supposed to be around five , so I finally took time to mess with my v2 and figured out how to use it a little more. Thanks for taking time to help me out. That's why I love this forum.