Ok I decided I needed to help everyone out a bit by telling you exactly what you need to install an aftermarket tach in the Ecotec Cavaliers and sunfires, not sure about any other cars.
Ok the problem with installing an aftermarket tach is that the ecotec uses a distributorless ignition system, so it has to seperate tach signal wires which are class 2 engine system digital, one wire for cylinders 1 & 3 and one for cylinders 2 & 4, so you need to convert it to one wire and and back to analog..............so how in the hell do you do that you say, and your probasbly scratching your head by now, ok so I'll make it easy for you, go to your local MSD dealer and order this...........
--->Distributorless Tach Driver - PN 8913
and heres a link to the website with info on it
MSD distributorless Tach Driver
Now wire it up between the ICM on the top of the engine, you know the little silver ridged wire harness thing that is connected to the plastic that says ECOTEC,ok heres a pic showing the thing I'm talking about. Its on top of the engine on the right hand side.
Then just wire your Tach in, mount it, connect the tach's power wires, and connect your tachs signal wire to the NEW signal wire on the MSD Tach Driver. Simple if you do itright the first time.
I've found the Tach Driver from 99 bucks to 60 buks just depends on where you buy it. Hope this helps you guys out, it took me like 2 months of research and someone from JBO's help to figure this out, but now its cleared up so hope it helps, later, James
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Hey, great info..I get asked that by people all the time, lol.. <br>
RIP FF22: 1996 - 2003 (1996 Pontiac sunfire 2.2 OHV, showcar) <br>
<img src="http://images.cardomain.com/member_images/4/web/436000-436999/436638_13_full.jpg">
Sticky?
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2004 Electric Blue Sunfire.
Yeah I was thinking that myself because I see this question like all the time on JBO, so I figured I'd put it up here for us.............any oyther info like wire colors would be great though, once I get mine wired up I'll get pics and put them up here for all to see, in the mean time heres a link to the wring harness diagrahm so you can find the wires for yourselves if so inclined..............
Ecotec wiring diagrham for PCM
Hop that helps you all, I'll get more info soon and post it up here, along with some pics, later on................James K. <br>
Ok got more info about the tach driver install, here it is,
The instructions say to wire the HOT (red) wire from the tach driver to a 12v ignition source----IGNORE this.
Go directly to the diagram that is supplied with the tach driver and follow the diagram for the chevy pink wire (you will know what i am talking about on the diagram).
The tach driver has 4 wires coming from it-
red - 12v hot (ICM)
black - Ground
red with green stripe - to pink wire in ICM
grey - To tach (to ractive's green tach signal wire)
1.Now by following the diagram you are going to find the PINK wire from the ICM and cut it! (give yourself a good amount of wire to work with on each side of the cut!!)
2.Now connect the half of the PINK wire that is still connected to the ICM to the RED/GREEN wire.
3.On the half of the PINK wire that is no longer connected to the ICM and is running down toward the starter you will need to connect the RED (hot) wire.
4.You can then connect the BLACK wire to a ground (the battery plate is a good close spot), but make sure to sand whatever area you connect it to in order to get a good ground.
5.Then connect the GREY wire to the tach's signal wire (green-on ractive tach).
6.Then proceed to wire you Tach as you would via its instructions.
7.Enjoy the accurate reading (not dumbed down for fuel economy) of the engines RPM's!!!
Hope that is a better set of the actual Tach Driver install instructions, better than "Now wire it up between the ICM on the top of the engine and the tach."LOL
Hope this all helps you out.............Later, James <br>
so, what you are saying is, you can just splice into the stock tach?
No what I'm saying is you CAN NOT splice into the stock tach, its class 2 digital, an aftermarket tachometer is analog and runs off of electricity and signal strength.
The best way to describe it is, you can't pick up cable with bunny ears, and you can't run class 2 digital into a class 1 analog tach........
1.What I'm saying is order MSD Distributorless Tach driver- Part Number
#8913
2.Splice it into the PCM, using the wiring diagrham and instructions I supplied
3.Then wire the tach to the MSD tach Driver
4.Then wire power, ground, ignition of tach, mount tach and enjoy accurate shifts!
...............its that simple...............
Hope that helps also, later, James K.
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or just not be cheap and buy a tach compatible down to a 2cyl. motor like I did... <br>
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