Misnblu's Ignition Writeup

Preview:

    To do this mod, you'll need to have a Haynes or Chiltons manual for a reference. 

    You will need to know something about reading a schematic but not be an engineer to read these simple schematics and to read wiring diagrams. 

    You will have to do some things by trial and error as I did because it won't fit perfectly the first time, so don't be discouraged with it. 

    You'll have to do some fabrication, modifying, and not be scared of making mistakes or not getting it right when doing this particular modification.    It's all worth it in the end so be patient.

    Letters in parentheses will reference to certain pages in the manual from Chiltons or Haynes. 

        (a) See page 5-5 of Haynes manual, fig. 6-17a, 6-17b to see what I mean.   Also see 5-6, figure 7.10

        (b) See page 2-2 of Chiltons manual, fig. 1 for location,  page 2-5, fig. 13 for DIS assembly pics

        (c) See page 2-5 of Chiltons manual fig. 13

Let's get started:    See Page 1

    First, you've got to hit the junkyard and find the white ignition coil housing assembly from the 2.3 or 2.4 engines and remove the wiring harness that connects the DIS coils under the IDI cover to the ICM, under the cover too.  See (underidipic) for a reference.  

    Make sure you see the three prong (a) plug with the 2 white wires with one brown wire that is part of this harness, you'll need this for the project.     It's this plug that you want and leave enough wire to work with so that you can make your connections later to the new DIS coils. 

    Second, remove the DIS coils and the complete assembly bracket which includes the ICM under the DIS coils and fastens to the engine under the intake manifold of the '95-'97 2.2 OHV (b)  engines.

Do not use the DIS assemblies from the '98 or later engines which are mounted on the side of the engine, battery side.   They are internally wired differently and won't match the diagrams or schematics of what we're about to do here. 

    Cut the 5 prong, 2 prong plugs with some wire to spare that are a part of this assembly, you'll need these later so make sure you keep them on the DIS assembly you're removing.

    The entire assembly should be easy to remove as a unit with the DIS coils in place.   There should be an aluminum bracket holding this assembly to the underside of the intake manifold with 3 bolts attaching it to the engine. (a)

             (a) See page 5-5 of Haynes manual, fig. 6-17a, 6-17b to see what I mean.   Also see 5-6, figure 7.10

             (b) See page 2-2 of Chiltons manual, fig. 1 for lacation,  page 2-5, fig. 13 for DIS assembly pics

Step One:    See Page 1

    Next, remove the aluminum bracket that attached to the engine, holding the DIS coils.   There should be 4 screws that attach directly to this bracket which will seperate the mounting bracket from the DIS Coil assembly.  (c)

    Once removed, the 2 coil packs should just come off of the assembly revealing the ignition control module under the DIS coils.   On the bottom side, you'll see an aluminum plate which will need to be carefullly removed using a scredriver, prying it off from the side of the assembley.   Don't worry about destroying the internals of the ICM as that will be gutted anyway.

    Once this plate is removed, you'll have to remove all of the gel that encapsulates the ignition circuitry.   It's messy but easy to remove.   Next, with a screwdriver, remove the electronic components that make up the ICM until the inside of it is clean and only the connections are left to wire to.  (See diagram)

    Be careful not to damage or dent the thin aluminum plate that the electronic conponents are glued to.  

Cut any small wires that attach to the longer electricol connections and clip off excess wiring according to Diagram B.    It should look just like what is in Diagram B.

         (c) See page 2-5 of Chiltons manual fig. 13    

Step Two:

    Connect the internal wiring according to the Diagram B.   I used 12 gauge wire but 14 or 16 gauge wire should should be appropriate, just make sure you use good wire for the job. 

     These will have to be soldered and the connections of the ICM will have to be wire brushed to remove the coating so the solder will stick to the connections in the housing of the ICM that was gutted.     Use stranded wire wire that is insulated and not bare copper wire.

Step Three:

    I used an L-bracket which was made from stainless steel from a c.b. mounting bracket for a c.b. antenna and used for mounting the assembly onto the strut tower, drivers side. 

Radio Shack should have this or any truck stop that carries c.b. equipment and make sure it's a mirror mount, right angle style.   You can use any stainless style or aluminum, whichever you prefer.    I like stainless persnoally and got that to work.

    Drill the aluminum baking plate from the ICM of the DIS coil assembly using the L-bracket (4 hole) as a template for the holes on the plate. 

    Make sure you pay strict attention where each hole is going to be drilled.   Make sure you have room for bolts/ screws to have access inside the ICM reservoir so the aluminum plate will fit perfectly flush as it was originally.   This is critical to keep moisture out, keep that factory look, and will have to be trial and errored to make the best fit with where you'll be drilling.

    Make certain that your screw/ nut assembly will not be hitting any of the internal connections you've wired for the DIS coils.   You don't want any short circiuts here and make sure you use small head screws. 

    Once you've drilled your holes in the backing plate, reassemble it all back together for fit and flushness.   You may want to use a #10 size screw for the l-bracket to backing plate assembly and some 1-1/4 inch long screws to mount the DIS coils to the new assembly.   I used stainless steel screws for my setup and got a variety of length of screws, nuts, and bolts from Wal-Mart in their hardware section.

    Don't be discouraged if things don't fit perfectly the first time.   Trial and error with some fabrication will be necessary as this is a truly custom modifaction. 

Step Four:

    Once the new DIS assembly is done, everything fits perfectly, it's time to do some more wiring  and get ready to use the two plugs on the DIS assembly you just customized.  

    There should be two wire connectors on the DIS assembly, one 5 pin and the other a 2 pin.  The 2pin plug should have letters A and B on the side of the plug, designating each wire on the plug and is being called plug2.     The same is true for the 5pin plug and should be labeled A, C, D, E, and F and is being called plug1. 

    On these plugs, we're not worrying about the color codes on the individual wires, just the lettering, as described above, to make things easier to wire.

    I used (plug1) letters A for the 1/4 DIS unit trigger connection and letter B on plug 2 for the common return from the ICU of the 2.4 setup.      Letter F from plug1 will be joined or spliced with letter A from plug2 which will be used for the 2/3 DIS trigger and makes both plugs utilized so there are no open jacks on the custom DIS assembly.  The internal wiring of  the DIS assembly was easiest to wire this way.  See Diagram B for more of what I'm talking about.

Step Five:

    I located the new DIS assembly on the driver side strut tower.  I made sure it was low enough so the DIS coils would not touch the hood when closed or their spark plug wires. 

    A single mounting hole was all that was needed to keep the assembly solid on the strut tower and with the way the l-bracket is configured on your DIS assembly, should have made this quite easy to do.

    Make sure you use a short enough nut/ bolt assembly on the l-bracket mount to the strut tower so that you won't have any interference with your strut/ spring assembly. 

Last Step:

    Now it's time to disassemble your existing ignition system by removing the IDI cover assembly from your car.   Once removed, unbolt the ignition coil housing assembly, unplug the DIS coils from the ICM, and remove the ICM from the IDI cover which is held in by 3 screws.  

    The ICM should be sealed from moisture so there should be no worry about leaving it open under the hood of the car.  Since it needs to be heat sunk to dissipate heat, you'll have to fabricate a way to do this and make sure you use heat sink compound grease, which you can get at most computer shops or your local electronic shop.    This compound helps to remove heat to the heat sink area much more efficiently than just metal to metal contact.

    I used a CPU heatsink from a computer and it worked great.   It fit the ICM perfectly with some fabrication to make it stay in place and works better than factory for cooling.   See the picture of my setup to get a better idea on how this was done.  

    Next, wire the ICM plug you got from the junkyard from the 2.3/2.4 engine and wire it according to Diagram B.   I pretty much did this last as I mounted the ICM, with a bracket to the brake line housing so that I didn't have to modify the 11 pin harness that willl plug into the ICM.   I really didn't want to extend all of those wires to relocate the ICM and worked out great.    It also gave me the capability to reinstall it back to factory in no time with no other modifications needed to do so.

    Once everything is mounted, check all of your wiring, loom the wires you've made betweeen the DIS coils and ICM.   Buy some good EMI, helically wound spark plug wires so that EMI (electro magnetic interference) won't have an effect on the electronics of your car. 

Finally:  See Page 2

    This was originally done for an aesthetic appeal as I loved the looks of the engine without the IDI cover every time I changed the plugs on the car.   It turned out to be a performance mod that I would've never dreamed would work this good and am proud that is was done, and to my specifications.

    It's been proven to work on my daily driver with more spark energy, super throttle response, a 2mpg increase for every tankful, and a guesstimate 10-20 hp added as a benefit.  

   The hp figure is a guess as the butt dyno really tells me this is the best mod added to the car yet. 

   On the spark plug wires, it's your choosing on what you want to use.   I'd suggest using helicoil designed cabling as this eliminates any EMI from damaging your ICM.   Get the best you can afford, it's worth it.