Cummins 605/2050 immediate RPM drop issue

[WICT800]

(10-21-2021 )tree98 Wrote:  What makes you think the cause is the air throttle closing and not something else?

That’s what I’ve been trying to figure out, what is causing that air throttle to rapidly change position, from my understanding it sees signal from the EGR but with no check engine light I have received little help from the Cummins dealer. I’ve also made a mention that the truck turbo flutters out of the breathers on shut down which seems odd to me but the mechanic said “it’s programmed that way”. Believe me it’s been very frustrating, I have several videos of several trucks and none of behave this way.