A buddy of mine has all the stuff to wire up his 97 2.2l cavalier with megasquirt II. However, we are needing a little bit of help figuring out what all he will need to use as far as sensors go (the essentials).. and then what the acronyms on the megasquirt wiring harness meen so we can connect the sensors. Also would some basic numbers to start out with that would be similiar to the factory settings so we can work from there. If anyone could help or has knowledge of the megasquirt programs, please reply and I can give you some specifics on what Im working with, it would be greatly appricitated. Ive looked all over the megasquirt forums but could not ffind the answers Im needing. He is running the standalone by itself, without the ecu. Thanks!
Post up some specifics so we can help?
Heres the best help your gonna get here: MSEFI.com <-go there, ALL the info is there. It's all standard for GM, no point in trying to get people to re-invent the wheel. Any info you could ask here is already answered over there.
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
To elaborate, the sensors...you need to find all that info @ MSEFI.com, thats all I can tell you, it IS all there. For the base tune, you can get a base tune there too, or setup the MS to run an auto tune and go from there. For the timing, I'm not 100% sure on the crank reluctor wheel but I'd bet your best option would be to mount up a EDIS trigger wheel onto your crank pulley cause the stock reluctor (if similar to the 2.3L/2.4L ie: 7X) SUCKS balls. Too many work arounds and crap, just mount up an actual trigger wheel and go from there.
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
Sedtag1 wrote:A buddy of mine has all the stuff to wire up his 97 2.2l cavalier with megasquirt II. However, we are needing a little bit of help figuring out what all he will need to use as far as sensors go (the essentials).. and then what the acronyms on the megasquirt wiring harness meen so we can connect the sensors. Also would some basic numbers to start out with that would be similiar to the factory settings so we can work from there. If anyone could help or has knowledge of the megasquirt programs, please reply and I can give you some specifics on what Im working with, it would be greatly appricitated. Ive looked all over the megasquirt forums but could not ffind the answers Im needing. He is running the standalone by itself, without the ecu. Thanks!
Sensors.
I will suggest a GM 3-wire Coolant Temp sensor. Comes from a 93 Cavaler, 2.2. You'll also need a plug for a TPS sensor to go with that. This will allow you to run the Megasquirt from one lead, and the stock ECU from the other lead so that your gauge will still work. This is how I have my MS set up in my car. Running the MS by itself will work.... however things get goofy from there. For one, the factory computer does a number of things other than run the engine. It runs the gauge cluster and DRL's (You'll have 1 headlight without an ECU even if you clip the wire for the cluster), and some of the dash board warning lights.
What sensors do you use? The ones that are already on the car, simple as that. Pretty much everything you read about on a megasquirt, they're usually talking about using GM sensors. The one thing though, you will probably end up using the internal MAP sensor rather than the one on the engine.
To set up your crank trigger you follow the instructions for GM DIS. Which will tell you to set up the MS like it's for GM HEI, but a couple of settings are different. Not really hard.
I don't know of anyone that's using MS on a 2.2 engine. So you might have to tune it on your own. AutoTune...... won't do you a whole lot of good. You won't just turn it on and drive around and have a perfectly tuned engine. It's better tune it by hand as much as possible, then let AutoTune do the rest. But then still go over it by hand.
www.gmscf.com
Thanks guys, I think well get it figured out. We found a GM technician here in town that can help. He supposed to get back with me here within the week, and he will be able to help me get setup and give me some ideas on where to start everything at. I just thought mabe someone on here had tuned a 2.2l before with megasquirt, and if so, mabe they could help me get setup.. not to reinvent the wheel. Again.. I appriciate the help.
It's kind of a PITA at first. But once you start figuring out how things work and what you're looking at, and what you're doing when you push buttons on the laptop, it's not so bad.
www.gmscf.com
ok, so all this kinda brings me to a new question.. and that is, is it possible to overcook the stock fuel injectors with this programs. Im afraid that for the setup well be using, well need a more advanced fuel system, mabe an injector upgrade? Is there anything out there upgrade wise for the side feed injectors on a 1995-1997 2.2l? Im running an inline fuel pump that puts out plenty of fuel. Was told its possible we might have to upgrade to the newer 98-01 manifold that has the different style injectors? Guess I didnt realize that the newer style intake would me more efficient then the one I have. I was just hoping I could upgrade the injectors.. but have yet to find an upgrade.
Yeah, you can end up maxing them out. I've actally messed up on one of my settings and somehow got the injector duty cycle at idle pushing over 200% (which is actually impossible). All it did was start sputtering and pushing a bunch of black smoke out the tailpipe.
If you get too far overboard with things you'll know, and will be able to go back to a previous tune (make sure you save before working on a tune) to correct what you did. Just don't leave it on for a prolonged period of time if you know something is wrong.
www.gmscf.com
Stock bottom feed pfi injectors are shown with a max fuel pressure allowable of around 90 psi, IIRC. With a stock 94 engine using the OE injector running max allowable fuel pressure and a small turbo I was able to build boost to 6 psi at low rpm but had to constantly decrease boost as rpm increased to keep below 90% duty cycle. My solution was to switch to (4) TBI injectors from a 92 Saturn SOHC engine and decrease fuel pressure to around 14 psi at idle. These injectors are "very" low impedance peak and hold units, with resistance measuring around 1.2 Ohms per injector. If MS requires the injectors be wired in parallel you should check the MS documentation to be sure the injector drivers will handle the current requirements. Finally, these injectors will flow 52# / hr fuel @ 43.5 psi which can be a problem if MS fires the injectors in batch fire or bank fire mode rather than sequentially. Even with the low fuel pressure setting I used, the minimum PW required to deliver proper fuel at idle with the injectors firing 2X per crank revolution was below the minimum consistent "on time" which the injector could provide. I was able to use a special mode on my factory ecm which allowed me to increase the minimum PW by decreasing the number of pulses per engine rev but it required extra work to make the driveability right.
The 98+ intake manifold is not compatible with the earlier head. The more common route is a "top feed conversion" (search for it) where the injector holes in the 97 manifold are bored to accept traditional style injectors and a fuel rail from the 98+ engine is used to supply fuel. imo this is a good route to a good solution and will allow you some flexibility in choosing properly sized injectors.
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I was able to use a special mode on my factory ecm which allowed me to increase the minimum PW by decreasing the number of pulses per engine rev but it required extra work to make the driveability right
Megasquirt will allow you to do this.
www.gmscf.com
