I have finished assembling my Mega SquirtII and have it in and running. It is in my 1987 Pontiac Fiero Gt. I normally post on RFT but think you guys might want to see this to.
NOTE !!!! This is not for beginners, or someone who does not know much about how electronics work !!!!!!!!!!
Here is a pic of how it looks now (click to enlarge).
First thing you should do is pull the center cosole and take your stock ECU out. Look over the connectors and make sure you know how to tell what wire goes where(i.e. look at the wiring diagrams and know where the wire that is in A 1 goes). Next you should look over the list I made for what wire goes where, and figure out what wires you need to cut. I also attached the pic from the MS assembly guide and a url to the stock Fiero wiring diagrams. http://www.euronet.nl/users/fo_elmo/wiring.htm
The stock ECU turns the fuel pump on by applying power to the Dark Green and white wire that is in pin number A 1. This wire will be cut and not used for the MS install. MS does not apply power to the relay to turn it on it supplies ground. What you need to do to make it so MS can tell the fuel pump on is modify the wiring to the relay so that it truns on with a ground single NOT power. To get this done you need to get under the hood and pull out the air cleaner, there are two relays behind the it.
The fuel pump relay is the one on the right. It is easiest to take both relays off to rewire the relay. What I did is cut one of the Orn/Blk wires (both go to the same place) going to the relay and I also cut the Dk. Grn/Wht wire. I used a heat shrink but connector and wired the Dk Grn/Wht (which is the wire that the stock ECU used to turn the relay on) to the Orn/Blk wire (the wires you connect together should both come out of the relay) and reconnected both them to the Orn/Blk wire. What this does is applies power to the fuel pump relay where the stock ECU normally would. Next we cut the Blk wire going to the relay. This is the ground for the relay. If you were to not cut this the fuel pump would run all the time, even when the car is off. You should get some Blk wire ~18 gauge and connect it to the Blk wire coming out of the relay (the one you just cut). Run this wire into the cab of the car (I ran in through where on of the shift cable enters the cab) and connect it to pin # 37 of MS. This is what my relay looked like when I was all done.
The next thing you need to monify is the ignition module bypass output circut. In this circut the stock ECU applies 5v to the Tan/Blk wire located at pin D 5. What this does when 5v is applied is makes it so the ECU can control the timing advance while the engine is running. When the car is cranking/starting there cannot be 5v applied or the car will not start. MS has a 5v out but applies 5v all the time including during cranking. What you need to do is cut the Tan/Blk wire and wire it up to a relay (pin 87 of the relay) like shown in the pic below (it is not a pic of the ignition module we have in our car but is wired the same).
The wire that comes off pin 85 of the relay needs to have power only when the key is in the run position, and not during cranking. I ran mine wire up to the stock fuse pannel under the drivers side dash. I hooked this wire into the extra output for the radio. This extra spot is next to the radio fuse and takes a spade connector. Sorr but I did not take a pic of this. Run the rest of the wires according to the pic above.
MS has an on board MAP sensor and you dont need the stock MAP. I ran some 5/16 (not sure on the size) hosing from where the stock MAP gets its vacuume up through the fire wall into the cab and to the MS unit. Here is a pic of where the stock MAP sensor was and the hose running to the left of the screen is the new hose going up into the cab of the car.
Other than that I made a wiring harness for the MS unit. I went to the local electronic supply store and got some multi-color wire, a pinable DB37 female and male connector, and some un-insulated but connectors with some heat shrink. Her is what mine looked like when I was done wiring it up. I got the Male DB37 connector so that I could wire up all of the wires I cut going to the stock ECU pigtail. This way if I need to I can plug the two DB connectors together, hook up the stock MAP sensor, plug the stock ECU in and it fires right up. With it like this if I have a problem with my MS I can go back to stock and I can also now compare how the car runs (stock vs MS) and see if I have made any improvements on how the car runs.
Here is how I have it mounted in the car now, but I am making a peice of sheet metal bent up like the stock ECU. This sheet metal will bolt into the plastic bracket just like stock ECU does and I will just screw the MS to the sheet meatal.
Cool, keep up the thread, I take it you have a turbo 2.8?
The engine is bone stock. My plans are to learn how to use the software, and how every thing works, and then I will be installing a 3.4 DOHC engine using the stock fiero wiring harness. Later down the line the car will be force fed but that will be a while.
The engine is bone stock. My plans are to learn how to use the software, and how every thing works, and then I will be installing a 3.4 DOHC engine using the stock fiero wiring harness. Later down the line the car will be force fed but that will be a while.
Now THAT is interesting, one to look out for in the future (wonder if the wife will kill me if.........probably!!!)
With school being busy I have not had to much time to tune, but I have drove the car back and forth to school with no problems (~30 miles round trip). Today I went for a ride with a budy that has played with MS and did some adjusting. It does not run as good as the stock computer does yet but with a little time I will have good enough that anyone could start out with my file and just have to fine tune it from there.
Here are some screen shots of how Mega Tune looks and also how the Mega Log Viewer looks (this is how you look at your data logs).
If anyone would like to have these programs they are free. If you go to www.msefi.com there are people that put up their data log file all the time. Just down load one of them and you should be able to open it an see what the program is capable of. Mega Log Viewer: http://www.ideasandsolutions.biz/MSGraph/ Mega Tune: (if you get this you cant realy do anything untill you get the MS unit) http://www.megasquirt.info/megatune.htm
[This message has been edited by TurboGt (edited 03-01-2006).]
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09:07 PM
Mar 2nd, 2006
kwagner Member
Posts: 4257 From: Pittsburgh, PA Registered: Apr 2005
you should have just used the factory map sensor and changed the bins for it. requires a few extra wires, but thats not that big a deal. if i was to ms my fiero thats what i would do. of course, mine would be supercharged and have the 3bar map....
anyway, good work on the conversion, the harness looks great. another thing, ziptie that processor down lest ye lose it. i hear they can fall out when not mounted flat...
i have ms'ed a few cars, and if you need assisitance, just msg me. i may be able to answer. or, just go to the forums!
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01:02 AM
MikeW Member
Posts: 158 From: Phoenix, Arizona U.S. Registered: Aug 2004
Thanks for posting the info. I think you have the right idea, doing the MS first and then the engine transplant. Got a question. Since the 4 megasquirt drivers can run a V8, they must be able to run 2 injectors each. Could the system be setup to run 2 injectors silutaneously for the DOHC and render a semi sequential injection? I'm still sittling on my DOHC crate motor waiting for transplant time. I used to think MS only had 2 injector drivers. I haven't had my coffee yet some maybe I'm all wrong.
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10:33 AM
Flyguyeddy Member
Posts: 568 From: pekin, Il USA Registered: Dec 2003
you should have just used the factory map sensor and changed the bins for it. requires a few extra wires, but thats not that big a deal. if i was to ms my fiero thats what i would do. of course, mine would be supercharged and have the 3bar map....
anyway, good work on the conversion, the harness looks great. another thing, ziptie that processor down lest ye lose it. i hear they can fall out when not mounted flat...
i have ms'ed a few cars, and if you need assisitance, just msg me. i may be able to answer. or, just go to the forums!
MS comes with a factory 2.5 bar map that works out to 21psi of boost if you want. The gm factory map cant even read boost with out upgrading to a 2 bar map. Also gm's map sensors are expensive you can upgrade the MS map to a 3 bar for ~$40 compared to the $60-70 for the gm 3 bar.
You would have to have a large supercharger to push enough boost to want a 3 bar map and by then you could have put a turbo on for cheeper. But that is just how I look at it.
What have you put MS on?
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02:50 PM
tampalinc Member
Posts: 774 From: Columbia, MO Registered: May 2001
This week I will be doing a lot of tuning with school being out. I also need to play with the IAC settings, because I cant get a consistant idle from start to start.
I will let you guys know how the tuning goes.
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03:48 PM
Mar 30th, 2006
kingconnections Member
Posts: 219 From: San Antonio, TX Registered: Aug 2003
This is a great post ---I`m stealing/copying all the pics of the wiring diagrams as I`m typing --hope you don`t mind...lol... keep this thing alive.....Thanks....
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03:31 AM
Will-Martin Member
Posts: 1164 From: DFW, TX, USA Registered: Aug 2002
This is awesome! I've been wanting to try Megasquirt as well!
Since my Fiero isn't My daily...this makes a lot of sense to try. If I can get some confidence on the Fiero, the I might be able to finally make the leap for other stuff.
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09:12 AM
Mar 31st, 2006
gascarracer Member
Posts: 129 From: Batavia, Ohio, USA Registered: Apr 2003
Just so there's no confusion, the wiring diagrams are from the megasquirt site (I know you weren't trying to hide this, as the copyright is still in the images, but it's easy to overlook being gray on white). Thanks for the writeup, I will be consulting it in the near future
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08:45 AM
Apr 2nd, 2006
gascarracer Member
Posts: 129 From: Batavia, Ohio, USA Registered: Apr 2003
things that go bump in the night. Is this guy still alive?
quote
Originally posted by TurboGT: I normally post on RFT but think you guys might want to see this to.
My guess is probably not. Kinda odd, I was just reading a thread that bashed the hell outta these RTF guys. Just goes to show not all the apples are bad. An excellent article... far beyond my skill level at this time but very fascinating to read nonetheless.
Ð
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06:22 AM
watts Member
Posts: 3256 From: Coaldale, AB, Canada Registered: Aug 2001
