Question about low imp injectors, PWM, and flyback board..

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Question about low imp injectors, PWM, and flyback board..

Postby md95 » Tue Mar 15, 2005 11:15 pm

I was just wondering if I should use the flyback board for my setup. I will be using 4 Delphi low imp 780cc injectors on a 4cyl boosted motor. With that large of injector, i really need to keep the low imp "faster reacting" function of the injector, so i dont want to run resistors. I guess my question is that by using the flyback board, does MT/MS treat these as high imp by not even using the PWM feature(just flyback board), or do you still use PWM along with the flyback board? I know quite a few people just use PWM only with low-Z injectors without issue..I'm just thinking of long term durabiltiy/reliability of the flyback circuit..
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Postby TT350chevelle » Wed Mar 16, 2005 2:18 am

This is right out of the megamanual.

People running a number of very low impedance injectors have reported problems with the flyback circuit failing. Typically, this will happen with 4 or more low-impedance injectors, such as the Holley 85 lb/hr TBI injectors. This can be avoided by using resistors in series with the injectors, and disabling the pulse width modulation (PWM). However, a more elegant solution that continues to use PWM is the Flyback Board.

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Postby Fatbastard » Sun Sep 18, 2005 12:51 pm

Bringing this back for a quick question:

I'm in the exact same situation, 75lb/hr injectors (low impedance) but with a resistor pack. To disbale PWM, I'm guessing you would simply set PWM current limit to to 100%, and the Time Threshold to 25.4, correct?
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