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Old 04-11-2009, 02:28 PM   #45 (permalink)
consaka
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Join Date: Mar 2009
Location: Vancouver, WA
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Active Learning - '93 Chevy Suburban Silverado
90 day: 10.67 mpg (US)
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Quote:
Originally Posted by Coyote X View Post
Put a 22K resistor in for R2 in the picture and it seems to read properly now. Apparently I was only reading the very low end of the signal before because with the calibration I was using it is reporting 10gph at idle now

I will adjust the calibration now and hopefully it should be all good. I will keep the laptop showing the injector pulse width and keep track of the MPGuino for a while and make sure it is long term stable but it seems about right now.
At this point could you help me with some references because I am going to be having to do something similar. But I already know that 22k isnt going to cut it.
What size engine does this vehicle have? What is its idle gph? What is its redline no load GPH? What is its redline full load GPH?

I have been rereading this text http://www.tomco-inc.com/Tech_Tips/ttt38.pdf
And that whole peak and hold thing stinks because the signal is all over compare to the other. I take it what we are trying to do is shave the bottom and top off so we can just read the middle thats active the whole time the injectors are open.
Did you try reading the resultant signal AFTER the zener? I guess I am not sure what the zener is actually doing. Its a diode right?
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