Novajoe

Well I’ve been researching what it would take to adapt the megasquirt system to 05-06 2.2L. This is basically what I’ve come up with so far…

First off, I need to ditch the dbw throttle setup we have for a cable setup. I’m going to use the tb, cable, and accel pedal assymbly from an 03 cavalier.

Basically the fuel control is pretty straight forward. The megasquirt will actually wire into our stock injector clips.

Here’s a diagram from the megamanual site of basically how to wire the megasquirt up:


Basically everything on the fuel side is just as it looks. The ignition is a little trickier though.

As far as a parts list, this is what I’ve come up with for sensors and such
I'm going to need the ckp sensor, icm, tp sensor, air temp sensor, and coolant temp sensor from a pre-94 obd1 cavalier. I'm just going to use 93.

Here's how the icm and ckp sensor are going to be wired up for the most part. I've also learned that I have to keep the stock icm spliced in so that my auto tranny can shift properly(although I'm kind of worried about my ckp signal getting messed up). But the obd1 icm is going to be wired to the coils.


Also I’m informed wiring the knock sensor requires a little finessing as well. I’m going to need to pick up GM's Electronic Spark Control module. PN 16022621 should work.

Here’s a diagram of how to wire it:


This signal is fed to MegaSquirt-II by connecting the module output to an unused DB37 pin, and connecting that pin to JS4 (which goes to the 40-pin socket pin #30, then to PAD07 on CPU pin #34). However you need to reduce the module signal voltage since it is too high for the processor port directly. You can use the proto area on the V3 main board, a 1K Ohm resistor (1/4 or 1/8 watt), and a 4.7 Volt Zener 1W diode (Digi-Key 1N4732ADICT-ND, 36˘) to do this, as shown below:

However the knock signal by itself is not sufficient for detonation feedback ignition timing control MegaSquirt-II. You need code that responds to a 'knock' signal by retarding the timing. For MegaSquirt-II, this means using version 2.6 or higher code.

Wiring this up WILL throw codes. However you will be able to retain all of your stock functions like p/s, a/c, etc. However your coolant temp display in your DIC won't work anymore. But you'll be able to monitor it through megatune

Sw4y1313

Nice **** joe. What codes will this throw because i just moved into a new county where emission tests are not performed. If all else fails i suppose i could go to MSII and be good to go without having to worry about emission tests.

Novajoe

well as far as throwing codes... it's pretty much gonna throw all of em.

But the cool thing is that if hpt or sct ever comes out with editing software for our cars, you could find someone with the software to go in and just delete all of your codes. Then BAM, all the magasquirt with no codes. But as long as your areas inspection doesn't include checking codes you don't have anything to worry about anyway.

So far this is coming along pretty well. I've already got a base tune thrown togeather with megatune and ms extra software. Basically I'm running a set dwell of 50% duty cycle with inverted spark output and my TA advanced 45 degrees. According to alot of people this should run PERFECT as far as the ignition goes.

It's also pretty easy to change for your injector size. If you have a wb O2 all you have to do really is set your a/f targets, give a correct injector size, and the dam thing will practically tune itself.

I'm still messing with all the other cool little goodies on this thing. Overboost protection, water injection, 4 stage nitrous injection, launch control, etc. You can even set it up to run in both open and closed loop just like a factory setup. Has traction control functions yadda yadda. anything you can think of.

So far I'm looking at about 700 for EVERYTHING I need(would be 900, but I already have a wideband).

I'm hoping once I'm done setting the squirt up on my bone stock cobalt, I'll have a decent how-to put togeather with a complete list of parts needed and even a base tune.

IonNinja

all of that wiring makes my head hurt...its like wiring up 16 nitrous kits

I'm pretty sure though that I've read on one of the megasquirt sites that its actually possible to use our ignition setup with the new MS version...I swear I read that somewhere I just can't remember the site.

Novajoe

well you do kinda use our stock ignition setup. You just have to wire in an older ckp sensor and ignition module. Basically the ms can't break down the signal from our newer ignition module.

Now the trick is to hardwire both ignition modules in at the same time, just have the obd1 ignition module controlling the coils. But our stock ignition module needs to be there mostly so that the transmission shifts properly. I'm pretty sure you wouldn't need to do this with a manual transmission.

The wiring really isn't that complex. It's just a matter of hooking up one thing at a time.

denlou

Yeah at first glance it really looked intimidating, but once you break it down componently, it's actually fairly simple.

Psykostevo

What is a Megasquirt?

Novajoe

probably one of the most versatile standalone engine management systems on the market. Probably one of the cheapest too.

Omega_5

Cheapest... Hell yeah...
Most versatile... not so much... the Haltech and Motec controllers are far more amazing.

Psykostevo

Oh, Had no clue.

Smitty1017

will this allow for the shift point (tranny) tune as well?

Novajoe

nope... engine only

although you can alter your shift points

Yea those are some top $$$ SEM systems. But the megasquirt is pretty open. People are constantly coming up with new gidgets and programs for it all the time.

06_ion2

so with a electric tb you have to switch to cable driven tb? if you go standalone???

IonNinja

heres the thread I was looking for, stating that we could possibly use the coil on plug setup with the ms2 extra firmware

https://www.cobaltss.net/forums/***************************/viewtopic.php?t=2118&start=0

Novajoe

Yes you can use the stock coil on plug ignition. The only thing you have to change is the ignition control module and the crankshaft pos sensor(as far as wiring the ignition goes).

correct. The current megasquirt doesn't have the ability to process the drive by wire setup. So you need to swap the throttle pedal assymbly, tb, and throttle cable from an ecotec that comes with the cable throttle setup. It's easy enough to find in a junkyard.

I've heard rumors that the next gen megasquirt is going to have drive by wire capability though. But I'm not sure how credible that is.

as far as hooking up an 05-06 ignition system, I've already stated that you need to wire in a new ignition module and crankshaft pos sensor, but here's how to wire everything up.

We don't really have a coil on plug setup. We have 2 coils set-up for a wasted spark method. The 07s went to coil on plug I believe.

Of course the easiest way to go about this is to purchase a pre-built squirt. This one has everything needed and all you need to do is run the necessary jumper shunts to make it work with our ignition(which the ecu comes with).

http://www.diyautotune.com/catalog/m...a84ac1a56b5e41

And as far as externally wiring the system, here's a basic diagram for that as well.

IonNinja

I'm confused though, how can you use our current ignition setup if you get rid of the ICM? sounds to me like you'd have to get a coil pack and run wires to the plugs (like a Ford setup)...

07SSCharged248

i dont know what the **** is going on but... Rep+

Novajoe

You don't get rid of the icm. You leave it there so that the stock pcm knows where the engine rpm is and the auto tranny can shift properly and your guages work correctly. All you're doing is disconnecting the stock icm from the coils, and connecting an obd1 icm to the coils, and splicing the obd1 icm into the crank pos signal.

at least you're honest about it