Author Topic: Trigger question  (Read 18771 times)

Offline rob@vems.co.uk

  • Hero Member
  • *****
  • Posts: 3115
  • BHP: 49
    • VEMS Forum
Re: Trigger question
« Reply #15 on: November 15, 2007, 10:14:16 pm »
If you have cam sync then definately, even without as long as you know TDC then yes as well,

Offline pete95zhn

  • Jr. Member
  • **
  • Posts: 42
  • BHP: 4
Re: Trigger question
« Reply #16 on: November 16, 2007, 06:33:50 am »
If you have cam sync then definately, even without as long as you know TDC then yes as well,

Well, VEMS should get TDC twice per one engine work cycle ( 720 deg ), so in that case it could be feasible?? Is there anything else to change besides h[0] table?

Offline rob@vems.co.uk

  • Hero Member
  • *****
  • Posts: 3115
  • BHP: 49
    • VEMS Forum
Re: Trigger question
« Reply #17 on: November 16, 2007, 08:32:40 am »
Which cylinders are coils h[2]=31 22 31 22 connected to?

Assuming a 1, 3, 4, 2 firing order, and that injectors are wired: 1 = 01, 2 = 02, 3 = 04 & 4 = 08
Then if 22 is firing 1 & 4 and 31 is firing 3 & 2 then we know that we know that we can fire the injectors like so:

h[0] = 02 08 04 01 .. .. .. ..

If 1 or 4 is firing then we know that these cylinders are approaching TDC and that the valve will be closed, so its fine to inject on either of  these cylinders, and the same for 2 and 3.

This will mean that you get a much better level of injector control and that the fuel sits in the inlet and evaporates due to the heat of the valves, and as a result you get better idle with lower hydrocarbon emissions, and crisp throttle response.

Offline pete95zhn

  • Jr. Member
  • **
  • Posts: 42
  • BHP: 4
Re: Trigger question
« Reply #18 on: November 16, 2007, 11:29:32 am »
Which cylinders are coils h[2]=31 22 31 22 connected to?

Assuming a 1, 3, 4, 2 firing order, and that injectors are wired: 1 = 01, 2 = 02, 3 = 04 & 4 = 08
Then if 22 is firing 1 & 4 and 31 is firing 3 & 2 then we know that we know that we can fire the injectors like so:

h[0] = 02 08 04 01 .. .. .. ..

If 1 or 4 is firing then we know that these cylinders are approaching TDC and that the valve will be closed, so its fine to inject on either of  these cylinders, and the same for 2 and 3.

This will mean that you get a much better level of injector control and that the fuel sits in the inlet and evaporates due to the heat of the valves, and as a result you get better idle with lower hydrocarbon emissions, and crisp throttle response.

Yes, the firing order is 1-3-4-2 and injectors are wired: inj A/1 = 01, inj B/2 = 02, inj C/3 = 04 & inj D/4 = 08, like you thought. I'll make the change, thanks!

BTW; here's a graphic output of my trigger log:



Thanks to fellow VEMS/Audi installer who did the conversion from bitstream to graph!

Offline rob@vems.co.uk

  • Hero Member
  • *****
  • Posts: 3115
  • BHP: 49
    • VEMS Forum
Re: Trigger question
« Reply #19 on: November 16, 2007, 11:41:55 am »
Dont forget that you'll have to sort your divider or req_fuel or both