A quick question about base timing

[-DSM2NR-]

Should base timing be at 5 degrees with the car is shut off or with the car running (idling)?

 

[steve]

Should base timing be at 5 degrees with the car is shut off or with the car running (idling)?

Both but you never know that it's 5* BTDC when the engine isn't running and without grounding the check timing connector or using the MUT to lock the ECU in check timing mode the timing at idle will float around 8-11* BTDC.

Steve

 

[-DSM2NR-]

DSMlink shows 5 degrees with the car shut off. With the car on and "GNDTiming" selected the timing is 5 degrees as well. With the car on and ground timing unchecked timing is around 10 degrees.

Does that mean that my timing is adjusted correctly?

 

[Quasimondo]

You won't know for sure unless you ground the timing and adjust it using a timing light. DSMLink or any ecu will calculate timing off of what they assume to be a base timing of 5 deg BTDC. If your base timing is off, the ecu timing will be off, but the ecu won't know any better.

 

[-DSM2NR-]

I can ground timing via DSMlink but you're telling me that I still have to use a timing light?

 

[steve]

I can ground timing via DSMlink but you're telling me that I still have to use a timing light?

Exactly. The ECU expect that you have synchronised the CAS in the process of setting the base timing. If your just looking at the output of the logger you have no idea what the real timing is just what the ECU thinks it is.

Steve

 

[-DSM2NR-]

The problem is that I don't have a CAS on my car.

 

[steve]

Then you can't do much about changing the timing all you can do is check it.

Steve