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75 L28 N/A Megasquirt Starting point?

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Alright guys,


My car is almost stock...6-2-1 header and 5spd swap


The stock electronics in my car are junk and i need to get my car up and running soo....


I've been doing a lot of research on MS2 v3.0 main board and what it takes to run it.


I know right off the bat that i need :


-Coolant temp sensor (CTS)

-Intake Air Temp Sensor (IAT)

-Throttle Postion Sensor (TPS) (most likely 240sx throttle body)

-Oxygen Sensor (EGO)(highly recommended)

-Stepper IAC (is this needed?)


My question is can i use the stock ignition setup and stock injection to begin with? I will have LS2/Yukon coils wired for wasted spark, ford injectors down the line...but i need a starting point.


I know LS2 coils require that you run a trigger wheel and sensor which takes fab and i cant get a clear on required parts.


-which trigger wheel and sensor do i use for an N/A setup?...there seems to be confusion.


I've found this link and its and extremely good write up but i'm not using my stock harness because its pretty fried. i also believe he's using a 80's distributor.



Am I missing any components? any recommendations?


the final product over the next couple of months should look like the below image.


My Ultimate Goal is a high comp L29, E85, ITB, Twin turbo monster....No i will not do an engine swap L28 all the way!


Thanks guys!!!!





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If your block has a working CHTS use it instead of a coolant sensor.  It works fine and it gives you a much better idea of what the conditions are around what is typically the hottest part of the head.  There's a couple of posts here with the values you need to set, or you can look at the FSM and derive your own based on the graph in there.


An idle valve is not necessary for basic functionality.  AFAIK there isn't any difference between how you should trigger on an NA or Turbo motor.  It's probably easiest to set up on 82 or 83 l28et because of the optical dizzy.  Any injectors should work provided they fit (or you can make them) and you pay attention to their impedance.  Having known values for opening dead time would be beneficial but can be narrowed down to within a couple of tenths of a millisecond through trial and error.

Edited by Chris83zxt
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There are a few posts here regarding exactly what you are doing. The problem is they are in several categories. Search MS section, Engine section, they are all over. For the most part though I believe you can run all that stock stuff with MS.


Also look around here:




The MS site has some L28 specific stuff actually.

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It sounds like you have a pretty good idea of what it will take.


Your distributor will work for RPM input to MS in "distributor" mode. For a long time I used a '76 VR distributor with my turbo motor, You just need to disable the mechanical advance inside by welding or epoxying the moving parts. Wiring a VR dizzy is actually easier to do than the 82/83 optical distributor, you just need to configure MS for VR input and connect the two wires to MS.


You can use a trigger wheel for RPM input and still use a single coil and distributor for spark output. I ran my car like that for about a year that way with a 6-1 wheel machined into the flywheel.


You don't need a IAC unless you want one. If the "dumb" Nissan bi-metal idle air bypass still works, you can use that to bump up the idle on cold starts.


You also don't have to use a stepper IAC, you can use a PWM IAC. The steppers theoretically should have better control over the idle, but many vehicles use PWM IAC valves. As a bonus a PWM IAC doesn't require a specially machined block like a stepper. To use a PWM valve you will have to mod the board when using MS1 or MS2. I'm currently in the process of wiring up a Ford 2 wire PWM IAC I grabbed off a Taurus. Not using the stepper IAC also frees up a few extra outputs from MS2 you can use for other things like tach or boost control.


Oh and I'm mostly talking about MS2-extra, which is now basically MS3's code on MS2 hardware. The MS2-extra documentation and firmware is located at http://www.msextra.com/doc/

Edited by Metro
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