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changing injections per cycle effects?

Posted: Thu Apr 09, 2009 12:21 am
by TraviZ
i changed my injections per cycle from 2 to 4, do I need to worry about any of my other settings such as cranking pulsewidth? I have had a problem with warm starting, .1ms of cranking is not enough and .2ms of fueling is too much. I was curious if changing the injections per cycle would effect the resolution of my cranking pw?

Re: changing injections per cycle effects?

Posted: Thu Apr 09, 2009 6:12 am
by Matt Cramer
Cranking pulse width always injects every ignition event, so that won't change. If your injector opening time is correct, most of the other things should be OK except you'll need to change acceleration enrichment, probably cut that in half.

Re: changing injections per cycle effects?

Posted: Thu Apr 09, 2009 10:16 am
by TraviZ
not the answer I wanted but thanks, so if cranking pw is every ignition cycle that means for my v8, it squirts 8 times per revolution?

that makes sense why .1ms cranking is not enough but .2 which is double the fuel is too much and I have to crack the throttle quite a bit to let it fire.

any tips how I can remedy this? I cannot do a .15ms can I?

Re: changing injections per cycle effects?

Posted: Fri Apr 10, 2009 6:50 am
by Matt Cramer
It squirts 4 times per revolution, actually. What size injectors do you have?

Re: changing injections per cycle effects?

Posted: Fri Apr 10, 2009 8:37 am
by TraviZ
50#'ers - 8 of them.

Re: changing injections per cycle effects?

Posted: Fri Apr 10, 2009 10:53 am
by Matt Cramer
Maybe try a little more priming pulse and less cranking pulse?

Re: changing injections per cycle effects?

Posted: Fri Apr 10, 2009 11:42 am
by TraviZ
ya im actually gonna give that a shot after some research I did last night here on the forums, my prime was 2. at 25F and at 160F it was .1, so I made it 2. across the board, i will give it a shot tonight see what happens.

any suggestion for a starting prime point? is 2ms enough or should I do much more?

Re: changing injections per cycle effects?

Posted: Sat Apr 11, 2009 2:32 pm
by S.Bretz
I have a set of 96ers and the cranking PW is set to about 1.3 around 80-120 degrees on a 1.9l. If you cylinders are about 1/2 liter (30ci), and you are using 50's, I would think somewhere in the 2-3ms range should be about right

I have my priming pulse set to 1.1 across the board, If I try to up it any more, the 96 pound garden hoses flood it out.

Re: changing injections per cycle effects?

Posted: Sat Apr 11, 2009 3:28 pm
by TraviZ
my cylinders are about 3/4 a liter but I tell ya with even a .2ms pw under 160+ temp, and .1prime, it will flood unless i crack the throttle.