LLY: knock-sounds like woodpecker above 2500rpm

[TRUBBS]

so i finally got my new to me injectors installed tonight. got the tank back in hooked all the lines up and bleed it out and fired it up. starts fine, idles fine and free-revs fine.
driving around, once you get about to 2100 and above it starts to knock bang really lound, sounds like a woodpecker or a midget under the hood punching the firewall.
im at a loss now and cant figure it out

anyone had anything like this before?

 

[Alliance1289]

Have you logged anything to see if anything is out of the norm during the conditions where the noise occurs?

 

[TRUBBS]

Have you logged anything to see if anything is out of the norm during the conditions where the noise occurs?

negative- im still trying to figure all the data log pid stuff out on the efi.
im hoping that i didnt end up eatting a piston or something

 

[FrankenMax]

Injector harness maybe? When my harness went out it sounded like a band of pissed off tribal men under my hood.


Sent from my iPhone using Tapatalk

 

[TRUBBS]

Injector harness maybe? When my harness went out it sounded like a band of pissed off tribal men under my hood.


Sent from my iPhone using Tapatalk

Did it still idle fine?

 

[FrankenMax]

Intermittently.


Sent from my iPhone using Tapatalk

 

[TRUBBS]

How did you fix it? Just ice pick it?

 

[DIESELMAFIAPER.LB7]

how do balance rates look?

 

[DBUSHLB7]

Injector harness maybe? When my harness went out it sounded like a band of pissed off tribal men under my hood.


Sent from my iPhone using Tapatalk

I bet FrankenMax is on the right track.

Any codes Trevor? Injector output circuit codes are sometimes traced back to the male pins in the bale connectors having poor seat/not fully penetrating the female connectors on the engine harness side. I had this issue on my truck and my injectors were knocking bad. Pulled on male pins for injectors 1 & 7 with small needle nose pliers to re seat them and bingo, Knock gone.

 

[TRUBBS]

Awesome, I'll dig into it more tomorrow & check codes.
Only ones I remember seeing are maf codes but I'll look again and see.

Jake, I'll try & figure out how to pull balance rates on the dashboard tomorrow

 

[FrankenMax]

I replaced my 1-7 harness and re flashed the ECM and she was good to go that was three years ago. It never gave me another problem.


Sent from my iPhone using Tapatalk

 

[DIESELMAFIAPER.LB7]

Awesome, I'll dig into it more tomorrow & check codes.
Only ones I remember seeing are maf codes but I'll look again and see.

Jake, I'll try & figure out how to pull balance rates on the dashboard tomorrow

ill try an screen shot the pids an were to go whats your email?

 

[TRUBBS]

[email protected]
Thanks jake

 

[SSchmi5519]

Just logging Duramax Imperial will tell a lot.

 

[Alliance1289]

Just logging Duramax Imperial will tell a lot.

This ^

I started with that and made my own PID selection file for when I log my truck.

 

[TRUBBS]

Just logging Duramax Imperial will tell a lot.

This ^

I started with that and made my own PID selection file for when I log my truck.

thanks, ill look into it all and see if i can figure out how to do it
im still a rookie when it comes to messin around with efi

 

[LWATSON]

I just fixed a friends LLY last week, #7 injector connector. It sounded just like you describe but it knocked at any RPM while you were on the pedal. I'd start by just making sure the plugs were all pluged in good on all the injectors.

 

[TRUBBS]

mine sounds more like its coming off of the driverside.
but ill check all conectors

not really sure what all im looming for in the logging but i figured out how to pull balance rates
at 648rpm
cylinder 1 is- 2.06mm3
cylinder 2 is- 2.80mm3
cylinder 3 is- -3.38mm3
cylinder 4 is- -1.61mm3


cylinder 5 is- 3.14mm3
cylinder 6 is- -0.05mm3
cylinder 7 is- 0.27mm3
cylinder 8 is- -2.64mm3


just for fun i did injector duty cycle at the same time and
injdc1-271%
injdc2-271%


on edit again-
it only does it under throttle, i tried to "ice-pick" it but couldnt get the stupid pick through the plastic.
so i tried to "crimp" the conector with some pliers and it still didnt change anything.
seams like its coming from either the 2nd or 3rd cylinder on the driver side.

 

[TRUBBS]

so i pulled the furthest back injector on driver side, it was fully covered with soot and had some oil copming out of the hole.
so now im pretty sure that the copper washer is not sealing

but now i cant get the stupid thing out of the head. what are you guys tips/tricks/ideas to do so?

 

[DIESELMAFIAPER.LB7]

so i pulled the furthest back injector on driver side, it was fully covered with soot and had some oil copming out of the hole.
so now im pretty sure that the copper washer is not sealing

but now i cant get the stupid thing out of the head. what are you guys tips/tricks/ideas to do so?

Big screw driver under the hold down spray some cleaner in around it to