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Injector resistor selection?
Posted: Sat Sep 18, 2004 5:46 pm
by sebastian
I am using a set of DSM 450cc injectors that are at 2.5ohm. What size resister should I get. I am currently using a 8.3ohm on each resistor, but I am having touble starting it. The car ran fine with the high imp injectors.
Resister size?
Posted: Sun Sep 19, 2004 1:48 pm
by MegaScott
Look at the Manual-
http://www.megasquirt.info/manual/minj.htm#injresist
maybe also here-
http://www.msefi.com/viewtopic.php?t=3266
Basically make sure your TPS settings aren't putting you into flood clear mode.
S.
Posted: Tue Mar 28, 2006 8:24 am
by tlivingd
The manual refrences MS-1 v2.2 main board.
does V3 requre resistors for the injectors? the V3 has a flyback design to it. I do not see this refrenced in the manual or the assembly instructions of the v3 board.
any help would be appricated.
-nate
Posted: Fri Apr 21, 2006 8:01 am
by ae1969
tlivingd wrote:The manual refrences MS-1 v2.2 main board.
does V3 requre resistors for the injectors? the V3 has a flyback design to it. I do not see this refrenced in the manual or the assembly instructions of the v3 board.
any help would be appricated.
-nate
Same question for me. Is the V3 require the resistors?
I am running 4 - 55 lb Siemens (2.35 ohm) ?
Thank you.
Posted: Fri Apr 21, 2006 6:53 pm
by Bernard Fife
To control low-impedanbce injector current you can either:
- use PWM and the flyback circuit (a separate board for V2.2, built in for V3 main boards).
or
- use resistors. The calculation is the same for V2.2 and V3 boards, as Scott says, use the calculator here:
http://www.megasquirt.info/manual/minj.htm#injresist
Resistor calculation is not an exact science, though, and if the car won't start with the specified resistors, you may have to lower the resistance about 15% to 25%.
Lance.