Low impedance damage
 

Hey,

So I made the mistake of running megasquirt Hi-res code on my friends 5.0 mustang without knowing that he had low impedence injectors. I began tuning it and was having sparatic issues over 3000 rpms and couldnt get it tuned right. I originally thought it was weak spark but it turns out this was probably it.


Could running low impedence injectors without in line resistors have harmed the board permanently? Do I need to put 10 ohm 10 watt resistors in line with each injector or can i use an equivalent and just put it on the actual injector channel from megasquirt?

Thanks!

Do the resistors, and hopefully you didn't fry anything.

probably didn't harm anything (but im not positive) 10watt 10ohm resistor on each injector's 12v signal.

http://img383.imageshack.us/img383/7924/diy001a9ne.jpg

yeah i was reading on MSextra.com forums. looks like the current limiting circuit was protecting it from any damage.

I have 4 injectors per channel (Channel 1 inj 1,4,6,7 ... channel 2 inj 2,3,5,8)

They are obviously in parallel. I could do the math and find an equivilant resister to put on each channels 12v supply instead of each individual injector right? I can do the math to find the resistance, i just dont know about the watts.

yeah, beyond any thinking/researching I want to do this morning :)

haha im sitting in senior mechanical engineering vibrations at 8am right now... my mind is somewhat going. Ill do the equivilance circuit. I believe 4 10 ohm resistors in parallel is equal to 1 2.5 ohm in series. I just dont know the watt ratings that I would need for that.

probably play it safe and go with a 50-100watt resistor with a built in heat sink.