MyE28.com DEV

I purchased a used Megasquirt board from a board member and want to verify what I actually have here.

I know its a MS3 board with a vacuum line attached to measure boost (I assume).

It was apparently built by Peter F. Whoever did it did a really nice job putting it into a stock ECU case. Well done

Here are photos of what I have (sorry for the High Res):



Here is the backside of the board:



And here is what I am assuming to be the driver for the IAC valve:



Other information that I have is that it was modified to run LS2 coils (but we will be running a single coil with MSD setup, which I was told should work correct?)

Any information is appreciated. I will wire up the wiring harness at home tonight to see if I can get this puppy to boot and see if I can read the MSII tune from it.

The vacuum hose is for the Manifold Absolute Pressure sensor. This is a speed/density metering system. It has to know the throttle position, the engine speed, and manifold pressure to work. It looks up how much fuel to add based on those measurements and a table of engine volumetric efficiency numbers that you input (with corrections for exhaust O2, engine coolant temp, and intake air temp.) The current tune will run an M30 with a single coil/MSD (that's what it came off of) but you will need to adjust the VE and spark tables for your motor. You will also need to add an intake air temperature sensor. I do not off the top of my head know which pins that connects to on the plug, but you can trace that easily if you look at the MS2 schematic for the V3.0 board.

That is actually a MS2 board. Nicely done too!

mooseheadm5 wrote:The vacuum hose is for the Manifold Absolute Pressure sensor. This is a speed/density metering system. It has to know the throttle position, the engine speed, and manifold pressure to work. It looks up how much fuel to add based on those measurements and a table of engine volumetric efficiency numbers that you input (with corrections for exhaust O2, engine coolant temp, and intake air temp.) The current tune will run an M30 with a single coil/MSD (that's what it came off of) but you will need to adjust the VE and spark tables for your motor. You will also need to add an intake air temperature sensor. I do not off the top of my head know which pins that connects to on the plug, but you can trace that easily if you look at the MS2 schematic for the V3.0 board.

The TPS isn't even needed other than for the overrun fuel cut and idle control. If you're running speed density all it needs is manifold pressure and RPM. Coolant temp and air temp are just correction factors, coolant temp being the more important of the two if you like your engine to start and run at room temperature.

turbodan wrote:

mooseheadm5 wrote:The vacuum hose is for the Manifold Absolute Pressure sensor. This is a speed/density metering system. It has to know the throttle position, the engine speed, and manifold pressure to work. It looks up how much fuel to add based on those measurements and a table of engine volumetric efficiency numbers that you input (with corrections for exhaust O2, engine coolant temp, and intake air temp.) The current tune will run an M30 with a single coil/MSD (that's what it came off of) but you will need to adjust the VE and spark tables for your motor. You will also need to add an intake air temperature sensor. I do not off the top of my head know which pins that connects to on the plug, but you can trace that easily if you look at the MS2 schematic for the V3.0 board.

The TPS isn't even needed other than for the overrun fuel cut and idle control. If you're running speed density all it needs is manifold pressure and RPM. Coolant temp and air temp are just correction factors, coolant temp being the more important of the two if you like your engine to start and run at room temperature.

Oh awesome!

I guess that means I dont need that flappy door AFM anymore! MAP sensors are probably better for this application anyway!

Life is getting better and better every day! HAHA..

The day of starting our Turbo Bav is getting nearer and nearer!

Keep us updated! I soon hope to start running MS for my e34.

So what sensors do people normally run in an ms setup?

MAP
coolant temp
Crank sensor
Wideband?
What else?

jodystevens wrote:So what sensors do people normally run in an ms setup?

MAP
coolant temp
Crank sensor
Wideband?
What else?

TPS
IAT

Are you asking what sensors need to be hooked up, or what specific part numbers and brands people use?

I used the gm iat, and water temp sensors. I used a tps from an mid 90s nissan pathfinder (same d drive) and mounted it to my backing plate w/2 screws. The gm water temp sensor doesn't match threads in t stat housing I had to retap larger (I cracked the first housing, so be careful if you go gm). Easy therm allows using bmw sensors, I just went gm to keep it simple. I mounted iat in intake manifold, but this causes heat soak issues,so you might want to mount it upstream, but after i/c.
good luck
marc

Guys, if you have questions regarding your own project, please start your own thread about it. This is twice now that we've had to split posts off this thread.