Popping Under acceleration

[Phoenix6189]

(08-18-2026 )Rawze Wrote:  To ensure it is not program related ...
Copy program from ecm and e-mail to to me for a review of what is in the ECU. For all anyone knows, it could be in need of software update, etc.

- Also, after backing up the ecu programming as is, re-flash it to latest factory software and run it around the block with the factory programming in it ans see if the issue clears up.

--------------------------------------
Mechanically, as far as the popping goes...

== If the overhead cam is not damaged / flaky and worn really REALLY badly then its not likely the cause.

== What wedge was used on the valve cam?. - You sure it was wedged right? and was not out 180-degrees?.


== It is all OEM turbo, manifolds, overhaul kit, head etc?.

== OEM injectors?.

== It it all matching components according to the engine ser#?


== What are the intake/exhaust valve clearances measuring at this point, now that is has a few miles of running on it?.

== Will it pass an injector leak test exactly as it shows in this video?..
info: https://rawze.com/forums/showthread.php?...3#pid75483

== What is boost getting to in a hard pull // hard acceleration when its happening?.

... and .. what are you calling a popping?...

... a 'Chihht' ... 'Chihht' ... 'Chihht' ... sound?...

or a distinct, sharp ... "Pop" .. ... "Pop" .. ... "Pop" .. sound,?..

??? or something else?.

is it subtle?... or very loud?... etc?.

and is it every revolution of engine?.. every few revolutions on the r3egular/... or simply random?..

I'll look up how to backup ECM tonight.
Cam looks fine. #6 Wedge, Wedged CAM and set insert pin on balancer. and Pin went in correctly.
Dumb question, is there 2 places on the cam the wedge will go in?
ALL Cummins parts in IN-FRAME, Turbo, injectors. Don't know for sure what they set the cylinder height to.
This time Cummins told me they only had a reman head available.
All parts came from Cummins for the Ser # everytime. Stopped going to the dealership after all i kept doing was go to Cummins anyways.
No miles on it. It started the popping under acceleration after I started it and let it get to temp.
Re checked Base Engine timing, and valve lash and they are spot on.
Did a fuel pressure leak down and it leaked around 900 psi. I'll rewatch the video and do it again tomorrow to make sure.
It's a pop-pop-pop, but its not consistent. Turbo pipe off not too loud, with pipe on its loud.
And it doesen't happen every revolution.
Lot of exhaust plum. Runs great at idle. I'll be taking a video of it tomorrow and see if I can get a more definitive answer.

And Crap Rawze, I had to check my Pants after your second comment.