Hello everyone.
Hooking up megasquirt ecu harness also called db 37.
1. There are 4 wires coming off the db37 for injectors and there are only 2 injector wires at the pcm. Do I need to tie the liked colors together at the db37 and only tap the 2 at the pcm? Or no I tap the injector harness at every injector for different firing sequences?
2. Where is the best place to tie the grounds from the ms and my lc1 together and ground?
3. Pin #24 says cranks positive. It means crank reference signal right?
4. Pin 36 says on the diagram that it goes to pin 36. Wtf? What does it really go to?
5. I am trying to find a intake temp sensor that it the thread in type for the megasquirt so I went to my work and found a few and tested the resistances off the car and they were pretty close like stock plastic sensor was 2.39ohms and the threaded one was 2.76 ohms can I use it for ms? Also cold side by the bov for placement?
6. The pin number 36 says ignition module/coil do I need to hook that up for fuel only and if so is that a power for the icm?
Thanks a lot guys
Jason
this is how my 2.4 is set up should help you understand it alittle better
R.I.P. Brian Klocke, you will never be forgotten
Boosted2point4 wrote:this is how my 2.4 is set up should help you understand it alittle better
Your an animal!! Get it running yet?
1. There are 4 wires coming off the db37 for injectors and there are only 2 injector wires at the pcm. Do I need to tie the liked colors together at the db37 and only tap the 2 at the pcm? Or no I tap the injector harness at every injector for different firing sequences?
Your car only has MPFI, correct? If it's SFI you'll need to rework the injector harness. But you should normally have 4 wires there on an MPFI setup I think. 2 of those (probably pink) get wired to a 12v+ when the key is in the ON and START positions. The other 2 would be your grounds for the injectors, and those run to the PCM.
2. Where is the best place to tie the grounds from the ms and my lc1 together and ground?
I would hook the MS unit up somewhere that it has it's own ground. Probably wouldn't be a bad idea to do that with the LC1 as well. If you can't find one, make one.
3. Pin #24 says cranks positive. It means crank reference signal right?
Yes, Not sure on the color. From the looks of Brandon's pic it shows a purple wire. And I think on my 3400 the wire from the ICM was purple.
4. Pin 36 says on the diagram that it goes to pin 36. Wtf? What does it really go to?
I think that might be the one I got confused on too. I bought a harness with mine, and I think that's the one that's the braided wire that runs around another. I believe it's a ground.
5. I am trying to find a intake temp sensor that it the thread in type for the megasquirt so I went to my work and found a few and tested the resistances off the car and they were pretty close like stock plastic sensor was 2.39ohms and the threaded one was 2.76 ohms can I use it for ms? Also cold side by the bov for placement?
Stock IAT sensor worked with mine. But If you want a threaded one, I believe there is a fast response sensor that's threaded. Looks like a coolant temp sensor, but the end of it's open like an IAT sensor.
www.gmscf.com
its running, but have a few little things to tend too. im kinda waiting on figuring out a few tables on extra code so i can change over to that finish up some idle stuff and then move on to load tests.
R.I.P. Brian Klocke, you will never be forgotten
so hows this gonna work without having the cps pad on the intake cam, still able to tune sfi and with this do you need the 2.3 icm to send the signal or the 2.4 icm able to work?
really looking into possible options cause hpt is starting to really piss me off
LAFNGAS wrote:so hows this gonna work without having the cps pad on the intake cam, still able to tune sfi and with this do you need the 2.3 icm to send the signal or the 2.4 icm able to work?
really looking into possible options cause hpt is starting to really piss me off
the wiring of the injectors looks like they would fire batch style.
Yes, that diagram there is batch fire and Jason's car is a 2.2OHV not the 2200 SFI so his is also batch in stock form so the wiring for the injectors will be the same.
LAFNGAS: You can not run COP or SFI without a CPS input as you mention. Only DIS and batch fire would be possible, however there is a segment Beta availalbe (full release in process) for the MS2Extra that will be able to run SFI with 4 independent inj outputs. All standard forms/versions of MS2Extra can run COP with CPS input for up to 6 cyl engines as is tho.
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
thanks josh,
i dont have the cps pad on my intake cam so that wont be possible unless i run the cam sync and the dis 2 which is looking what i may just have to do but im gonna wait til i get my car back together and turbo'd first
No, you can't run SFI with a crappy cam sync module....all that does is gives a signal that matches the sprk4.....hence the timing of the "cam sync" module will be advanced or retarded as much as the ignition is. It honestly probly would 'work' but you will never have it running right. If you really want SFI....start thinking about how you are going to attach a magnet to your cam gear.
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
not sure how id do that, figure somethingout i suppose when it comes down to it.
So, I made up a wiring diagram for a "barebones" fuel only setup with a few small bits of information as well already on the pic. Everything else you don't see in the pic, the factory ECU will run. Again, this is a BAREBONES fuel only setup. I can't think of anything I have mist....but that doesn't mean I didn't. Jason should have this tested soon and an update will be made if needed.
You really don't even need the "main relay" in there either but it is a good idea. You could actually just run a simple 15amp fused lead off of the ignition wire(hot in run and start) coming from the key cylinder under the drivers dash area/steering column.
Below is a diagram showing the optional power run for the MS unit, I recommend a relay instead, but this 'will work'....also it is a little bit better cleaned up on the VR routing and showing the wires continue to the factory ECU/ICM(depending on application)
Edited 4 time(s). Last edited Wednesday, July 15, 2009 10:25 PM
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
Scott my car runs fine in Batch Fire
i think i may be building megasquirt here soon
^Its seriously pimp
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
The turbo car is getting one!
Joshua Dearman wrote:^Its seriously pimp
haha every megasquirt thread is you talking it up and saying how awesome it is
haha. and ya i will prob be running it on the turbo car when i get there but idk if im ready to try it out on the other car cuz its the one i dd.
I cant help it......they just are! lol
To clarify, since I got asked a few questions already. If you brought in a straight square wave in from the ICM and dont give the MS a actual wheel map(ie: no shown skipped tooth) you will need to setup your fueling in 4 squirts/cycle(720degree roation). You could do it with 2squirts/cycle but this could create the situation where you are fueling a cylinder at both times when the intake valves are closed. By running 4 squirts/cycle you are 'almost' guaranteed a squirt while the intake valve is open(or at least closeer) to help smooth out the idle. 4S/C is basically just insurance...since you would have a 50% chance of injecting fuel in the cyl when the valves are dropped if you ran 2S/C. Obviously this is using a alternating sequence of injecting instead of simultaneous. Where alternating fires only INJ1 channel and then alternates and fires INJ2 channel on the next fire. Simultaneous is where both INJ1 & INJ2 channels fire at the same time. If you went Simultaneous you would only need to set the S/C to 2 and you would achieve the same results with a REQ_FUEL constant in the "Injection Control" being the same. Now if you ran 4 S/C and simultaneous then you'd half to cut the REQ_FUEL constant in half and would have massive intake runner fueling and would require EAE-walls tuning to help you get good drive ability and fuel economy. Not to mention you'd be asking the injectors to be operating 4X as fast as they would in SFI...so you gotta ask yourself if your injectors could physically keep up with fixed opening and closing times eating into your injection schedule at high RPM too. Kinda all plays together.
Sorry if this is a little off topic, but I think it is important to know and for those who are thinking about running the MS should really try to get a handle on these concepts.
Edited 3 time(s). Last edited Thursday, July 16, 2009 11:47 PM
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
jmarks82 wrote:gmanz24 (The Bash Whore) wrote:D-Mac wrote:Scott my car runs fine in Batch Fire
mine too.
Mine too!
Mine too!.
However, I recently changed my injector staging to alternating, and 2 injections per cycle. Seems to like it helped slightly to let it idle a bit smoother. Before I had it as simultaneous fire and 1 injection per cycle. Doing alternating injection events will also help a bit to keep fuel pressure up (probably good on a boosted car) since only half the injectors are open at once.
As far as SFI. Kinda pointless. It helps it run smoother and helps get a little better MPG. But my guess is that most of us that are MS'ing their car is probably doing it for some sort of performance reason, rather than daily operation. In that case, at WOT your injector duty cycle can end up being 80% or higher, but your valve might only be open for about 30% of the time. So might as well not worry about SFI, or trying to simulate it.
www.gmscf.com
^Exactly.......I bet you saw a nice 'roughness' reduction when you switched....and 2S/C/A will work just fine and will keep the duty cycle down...that for sure. I've always had better luck with 4S/C/A but it can give your injectors a work out. Going from 1S/C/S to 2S/C/A leaves you running the same REQ_FUEL but will help out with fueling quite a bit.(I know you know this SHOoff...just posting this for people who will be reading this to learn)
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
In case there is any confusion...I figured I'd try to simplify it.
So, the number of squirt per cycle is fixed....it wont change whether you decide to go simultaneous or alternating.
Now, simultaneous means all the injectors fire at the same time and alternating means INJ1 channel fires first and then INJ2 channel fires second....repeat.
So, if you want 2 S/C/S then you will have all 4 injectors firing at the same time...once every 360 degrees of crank rotation.
If you wanted 4S/C/A then you would have injection events every 90 degrees of crank rotation and would alternate between INJ1 and INJ2 and each channel would fire twice in one cycle.
IIRC the GM batch is 2 S/C/A...just FYI
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
^that 90 degrees mentioned should actually be 180 degrees sorry....
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
my car runs just fine in batch fire, was just inquiring
