Setup of duty cycle required ????

quattrodave · Post by **quattrodave** » Sun May 07, 2006 10:25 am

Hiya guys,
I've just got my first MS running and i have a few questions...
In the configuration and tuning guides it says :-

"You want this to be set so that your idle pulse width is no less than 2.0 ms, if possible, and your Req_Fuel is less than 15-18 milliseconds, but more than 8 milliseconds."

Currently my idle pulse is 1.8 ms and my required fuel is 5.1.
I need the big injectors as alot of boost is being run.
How do i get these figures within specification ???

Many thanks

Dave

TT350chevelle · Post by **TT350chevelle** » Sun May 07, 2006 10:40 am

The key word is "if possible" when you run large injectors for big power you may not beable to reach the recommend settings.Are you running a boost/manifold referenced reg? This also helps injector PW by reducing fuel pressure when idling.
Are you able to get a decent idle? If everything is running OK, don't worry about it.

Brad J.

Bernard Fife · Post by **Bernard Fife** » Sun May 07, 2006 11:08 am

quattrodave,

In additions to Brad's excellent advice (as usual!), the req_fuel size issue is less important with MegaSquirt-II, because of it's much finer pulse width resolution (100x better than MS-I).

So, to second Brad's advice, don't worry about it.

Lance.

boost junkie · Post by **boost junkie** » Sun May 07, 2006 12:31 pm

Mines worse. 2000cc engine with 780cc injectors. Idle pulse width is about 1.5ms. I sure with I had the 0.001 resolution. Can't wait for MS-II 'extra'.

quattrodave · Post by **quattrodave** » Mon May 08, 2006 11:36 am

OK.... In that case the question arises, How do i get a solid basic tune at idle whan changing figures around make little difference....??

Many Thanks

Dave