Rotational Velocity Question?

[Beanhead]

124K on the engine,fuel mileage went down a little,power is flat on the top end.Stock injectors and DP tuner.

I ran a rotational velocity test with my AE scanner.This is the results I found.

Cylinders #1 0.0 #2 0.7 #3 0.2 #4 0.0 #5 1.1 #6 0.0 #7 0.0 #8 2.8

Buzz test came out fine.

Question what is going on with #5 & #8?

 

[02BigD]

What is rotational velocity test measuring? (Not to be simple, what does that number that AE gives represent)

 

[Bushwakd]

What is rotational velocity test measuring? (Not to be simple, what does that number that AE gives represent)

Percentage of Cylinder Crank Deceleration (PID) also called (PERDEL) Crankshaft Velocity Change. Could be injector related or compression related. Unless having a grey CPS is in the mix therefore cylinder 3 & 8 fail the test while the black CPS turns out mostly all low numbers.

 

[Beanhead]

What is rotational velocity test measuring? (Not to be simple, what does that number that AE gives represent)

Answer for Rotational Velocity was answered by Bushwakd!

AE stands for AutoEnginuity scan tool.http://www.riffraffdiesel.com/mm5/m...RRD&Product_Code=SP03&Category_Code=F731-MISC

Percentage of Cylinder Crank Deceleration (PID) also called (PERDEL) Crankshaft Velocity Change. Could be injector related or compression related. Unless having a grey CPS is in the mix therefore cylinder 3 & 8 fail the test while the black CPS turns out mostly all low numbers.

Black CPS is on my truck.