injector staging

subie4me · Post by **subie4me** » Tue Oct 26, 2004 9:14 pm

I just burnt up the stock flyback circuit using low imp injectors 70% pwm with simultaneous staging. I tried alternating staging and it would not run right. Does anyone have any idea why it would not run right with alternating ? Would simultaneous put more of a load of the flyback ? This happened after I upped the req fuel from 7.6 to 7.8 on a 2.0 subaru running 18 lbs of boost.

MiseryQ · Post by **MiseryQ** » Tue Oct 26, 2004 9:18 pm

Changing to alternate doubles the REQ fuel so it would change the mixture quite a bit. Been there.

subie4me · Post by **subie4me** » Wed Oct 27, 2004 9:09 am

I really would like to know if using alternating is better for the flyback circuit. All of the info that I have read about using low impedence injectors does not mention the effects of injector staging on the flyback.

subie4me · Post by **subie4me** » Wed Oct 27, 2004 9:48 am

I really would like to know if using alternating is better for the flyback circuit. All of the info that I have read about using low impedence injectors does not mention the effects of injector staging on the flyback.

TT350chevelle · Post by **TT350chevelle** » Wed Oct 27, 2004 9:00 pm

Injector staging doesn't effect flyback, all it will do is change your duty cycle slightly.If your current setup had a flyback failure, changing the injector staging will not fix it, you need to upgrade the flyback circuit by using the flyback board, or use resistors inline with each injector.

Brad J.

MiseryQ · Post by **MiseryQ** » Wed Oct 27, 2004 9:06 pm

hmmm... I thought I posted earlier...

I used a large transistor for my low impendence injectors and never had any problems... That's another route you could take...

MiseryQ · Post by **MiseryQ** » Fri Oct 29, 2004 6:31 pm

Sorry I lost youe e-mail somewhere. Drop me another and I'll look it up for you.

MiseryQ · Post by **MiseryQ** » Thu Nov 04, 2004 4:09 pm

Been under the weather the last few days and had'nt had a chance to pull my MS.

It's a NTE393.

Matt Dupuis · Post by **Matt Dupuis** » Fri Nov 05, 2004 6:37 am

If you changed the staging from simeltaneous to alternating, and you still had one squirt / cycle, and your car ran crappy, here's why:

"one squirt / cycle" means that MS will trigger each injector once per 4 cycles. If you tell it to alternate, then MS will trigger one injector bank once in 4 cycles, and the other one in the next 4 cycles. Meaning, that if you've got alternating & one squirt/cycle in your settings, each injector will squirt once every 1440 degrees of crank rotation, or once for every two intake strokes.

Also, it will squirt twice as much per injection event, so not only does each cylinder not get any fuel every other intake event, but it gets twice as much as it needs the other 50% of the time.

If you're going to try alternating, you must double your number of squirts / cycle to maintain at least one injection event per injector per cycle.

If you knew that already, sorry.