Re: Diagnostic software
You are verifying that what the computer believes it has of timing is what the engine in reality has. Tolerances in plastic parts holding the CPS, magnetic field from flywheels, electronic components etc comes into play. There are no moving parts to 'adjust'.
-Start the engine, and hook up the timing light. As you have noticed, the timing goes up and down when engine is in idle.
- Go into timing verification mode of the software. The engine 'locks' the timing, and you will get a constant reading. At the same time, the engine might seem to run a bit unstable in rpm, let it do!!
- Read out the actual timing with the light, as an example 20 BTDC.
- From the software you get a reading of what the engine believes it is running at, as an example let us say 13BTDC.
You have a difference of 7 UP from what the engine believes it is running at.
-Go UP 4 degrees and press enter.
Go back in again into the verification process. Read out the REAL timing with the light, this time it might be 12BTDC. Read out the software what the engine believes it is running at, let us say 10BTDC. Difference is 2 UP. Enter the correction and press enter.
- Go back again and check, this time if both reading with light and what software says is the same. OK, and you are finished!!!
If not, one more time. Keep on until both readings are the same.
As the timing varies when engine is running, you will never get the same reading twice from the timing light, you have to stop the timing from cycling in the computer, but you never know where it stops until you start the verification process.