Why VR sensor = time based cranking?

hobieboy · Post by **hobieboy** » Mon Aug 07, 2006 7:08 pm

Hi,

MSnSe Setup page said that if using VR sensor, crank timing has to be time based (http://megasquirt.sourceforge.net/extra/setup.html). Why?

What would happen if I set it to Trigger Return?

My current situation is: I set to time based. With crank adance angle set to 0 degree, I can hear that the engine tries to catch & start. 5 or 10 degrees, nothing as if there is no spark. But, the engine still doesn't start yet. So, I'd like to try -5 degree (I assume this means 5 degree ATDC - not right for my engine, but heck, I need to try).

Can I enter -5 degree? Will it cause the code to go nuts?

thanks.

Post by **jsmcortina** » Tue Aug 08, 2006 5:42 am

The trigger return setting is intended for hall sensors where one edge of the vane occurs at say 60btdc and the other edge occurs at say 10btdc.

James

hobieboy · Post by **hobieboy** » Tue Aug 08, 2006 6:44 am

James,

Does it mean that trigger return means nothing to VR sensor configuration then?

And, to get ATDC timing, I just have to enter negative numbers, like -5 degree?

thanks.