Megasquirt FAQ, writeup (Updated 30/10/09)

captaingowa

New member
hoys":3j8n4dv2 said:
Sorry, I used the wrong word there, I meant to say how the pump is commanded to have two speeds. Looking at the diagrams now.

That's fine .. That manual is not specific to any vehicle and is just referencing a 7M engine, though the fuel pump control is the same for the ST165
 

hoys

Member
Looks like in my MS I just commanded the pump to always be high. Could easily be put on a programmable output triggered at engine idle speeds. No problems so far so I'm not too worried.

There is also the Fuel Pressure VSV that is normally used to raise the fuel pressure for cold start conditions, but I was interested in commanding it for higher pressure for larger injectors.
 

captaingowa

New member
hoys":21r627uc said:
Looks like in my MS I just commanded the pump to always be high. Could easily be put on a programmable output triggered at engine idle speeds. No problems so far so I'm not too worried.

There is also the Fuel Pressure VSV that is normally used to raise the fuel pressure for cold start conditions, but I was interested in commanding it for higher pressure for larger injectors.

You can do allot with by programming outputs.
I removed the fuel pump resistor pack, and fuel pump relay, and added my own relay and at the back of the vehicle close to my relocated battery, that was to ensure it received optimal power.
Off of the G1 connector I simply run the signal wire for the Fuel pump relay to the ECU.
 

lexinz

New member
engine stok 2000cc
injectors 540cc
turbo ct20b
ecu Ms3Pro
 

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Amate.GT4

New member
Hi i'm have thinks in buy the MSPNP2 for my GT4, and have quest....
The solenoid boost stock is good? Or best, buy the EBC of MS? (No have intention of up boost more than 15psi)
My fear is tuner the engine, read in forums and here, not look very dificult...

Thanks!
 

HiuBin

New member
This thread needs a serious update to the OP. It makes megasquirts look daunting to work with, and they are not.

You do NOT need to change your stock ignition setup. Stock works fine. An assembled Megasquirt-II unit (v3.57 board) will work right out of the box with just a few things that are required for any setup. (tachselect input, tachout, adjusting potentiometers). There is also Microsquirt. As a matter of fact I recommend it instead of the MS-II. There are more options out there that work better than the original megasquirt boards (MS-2 based clones that DIY does not want you to buy because it takes away from their sales, even though they're hardly "clones" and moreso improved versions with better hardware, VR sensor conditioners and pre-installed 4-bar map sensors)

However for the person that would rather NOT mess with an ECU's internals I would recommend using a Microsquirt for a budget solution, or a Megasquirt-3X or Pro for easier installation (you will still need to do some internal tinkering on a MS3X, but it will be far easier to wire up)

As of today, Megasquirt II and III does not like to use the stock ignition setup as-is, so you WILL need to modify that for it to work, I might make a detailed how-to on that later on if there is enough interest. However, you DO NOT NEED to spend ridiculous money on a crank/cam trigger setup to GET IT TO WORK. With that said, I DO recommend getting a crank/cam trigger setup INSTEAD because of various reasons, mainly that the megasquirt can default into crank trigger-only mode if the cam sensor fails (it soaks in heat the most) whereas the stock ignition's VR sensor might fail and leave you stranded.

Also, the stock ignition can't seal for shit, it always freaking leaks oil so there's that.

With that said, you WILL want to setup wasted-spark ignition once you do the currently-required mod to your ignition, as you will no longer be able to use your distributor to,well, distribute spark (you can, but it's much easier to change to a wasted-spark setup)

The beauty of Megasquirt is that you can use pretty much anything anywhere on the engine, so you can get any kind of wasted-spark coil, coil on plug, etc. that fits the engine the way you want it to and get it running with that. You CAN run full sequential ignition and injection on a MS-II but it requires enthusiast-level ECU soldering skills and circuit knowledge.

You can only run sequential IGNITION on a Microsquirt, it only has two injector drivers so you're stuck to, at best, semi-sequential injection (timed batch fire).

There's much more info to be given here but the point to take away from my post is, this OP is wrong and extremely outdated and spreads misinformation TODAY. It used to be relevant and accurate many years ago. It no longer is.
 

Gert

Active member
HiuBin":1jrem2b0 said:
Also, the stock ignition can't seal for shit, it always freaking leaks oil so there's that.
Isn't that a bit overrated? I modified my ignition to work with the Autronic somewhere in 1999 (or 2000?) and never had any problems with it, neither leaking.
 

HiuBin

New member
Gert":1zqhnf6t said:
HiuBin":1zqhnf6t said:
Also, the stock ignition can't seal for shit, it always freaking leaks oil so there's that.
Isn't that a bit overrated? I modified my ignition to work with the Autronic somewhere in 1999 (or 2000?) and never had any problems with it, neither leaking.

It's not. It's not hard to rebuild, regardless. And it lasts a long time when done with good parts, but it is still an issue down the road.

It does work fine though when you modify it, and it might work as-is (I'm working on a MS-based, cheap solution for that)
 

Gert

Active member
HiuBin":3sqx26w9 said:
It's not. It's not hard to rebuild, regardless. And it lasts a long time when done with good parts, but it is still an issue down the road.
If you say so. I build multiple 3S engines without any ignition problems like you stated. But, perhaps, Toyota sold better ignition systems in Europe ... :)
 

Magroo

New member
I think whats going on is the stock ignition system can be very "noisy" on the cam and crank signal lines because the high voltage is so close to it. MS1 and Ms2 didnt have a very good filter for it and can be tricky to get working right sometimes. I experienced this with the mspnp2 I have, to some degree. Once I switched to 1ZZ COP alot of my break up went away.

I'm still using the dizzy as a cam and crank signal, with wasted spark ignition. Im thinking about trying some other coils judt for kicks.

Subaru coils are already setup for wasted spark and are relatively compact.
 

HiuBin

New member
Magroo":1gb9gc76 said:
I think whats going on is the stock ignition system can be very "noisy" on the cam and crank signal lines because the high voltage is so close to it. MS1 and Ms2 didnt have a very good filter for it and can be tricky to get working right sometimes. I experienced this with the mspnp2 I have, to some degree. Once I switched to 1ZZ COP alot of my break up went away.

I'm still using the dizzy as a cam and crank signal, with wasted spark ignition. Im thinking about trying some other coils judt for kicks.

Subaru coils are already setup for wasted spark and are relatively compact.

Yes that is true, that is one of the reasons why a completely stock ignition will have issues on Megasquirt. Noise filtering is not the best with the VR circuit that is used on the MS1, MS2, Microsquirt and 3.0/3.57 boards. They improved the hardware for the MSPRO units but they are still fighting with noisy RPM signals from some VR sensor setups. They are working on a solution right now using a different VR conditioner circuit that they are beta testing, pretty much trying out what everyone else is currently using in their ECUs.

I loved using Camry 1998-2001 wasted spark coil packs on my ex-5SFTE setup (bought a Camry 98+ 5SFE complete engine and used that as-is)

The beauty of the camry coilpacks is that you can use 93+ 3SGTE cables on them (the clip-on style, not the press-fit 90-92 style) and it's easy to fab up a bracket to hold them.
 

MWP

New member
Eh... My MS3+MS3X worked with the 5S crank VR sensor and gen4 cam pos VR sensor straight off.
No adjustment needed, never looses sync all the way to 8000rpm.
Was almost too easy :)
 

HiuBin

New member
MWP":4xxidn5u said:
Eh... My MS3+MS3X worked with the 5S crank VR sensor and gen4 cam pos VR sensor straight off.
No adjustment needed, never looses sync all the way to 8000rpm.
Was almost too easy :)

That setup works just fine. I ran it for about 4 years on my 5SFTE (98+ 5SFE has a single tooth cam sensor mounted behind the cambelt cover)
 
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