Ford Duraspark replacement Ignition Control Module ICM
I replaced the Land Rover ignition control module (ICM) with a Ford Duraspark ignition module. Tons of thanks to Toddco for describing this "upgrade". I think that the Land Rover ICM is about $135 and I read many threads on d-90.com where our Defenders are having trouble with this part. So, I found a thread where Toddco describes a cheaper / better alternative.
Search for a thread titled, "Ignition Module and Coil?"
I did not find the Ford Duraspark ignition module for $16.99. Advance Auto Parts has one for that price but the one I was handed did not have 6 wires and the wire colors were wrong. NAPA has their store brand, Mileage Plus, for $29.99 (Part number: TP40SB). This module has 6 wires and in the correct colors (except for the black wire that Toddco mentioned.) Here's how I installed mine and the Rover started right up.
NOTE: These instructions assume that your original Land Rover ignition control module has been relocated out of the distributor. It is my understanding that 1994 Defenders had the ICM located inside of the distributor. There is a relocation kit available (do a search). On my 1995 the ICM was mounted on a plate bolted together with the coil. If considering the relocation I would assume that you can forget the kit, remove your ICM from the distributor, extend the red and blue wires, find some connectors for the coil and adapt these instructions to your Rover.
NOTE! NOTE! NOTE! I do not work for Land Rover. I am not a mechanic. I take full responsibility for what I do to my Rover and I do not take any responsibility for what you do to your Rover. These instruction worked for me and presumably at least one other person. Use these instruction at your own risk. My Defender is as it came from the dealer. 3.9 engine. No electrical modifications that should affect these instructions.
Finally, the instructions for replacing your Land Rover ignition module.
Go to NAPA and pick up part number TP40SB. Verify that it has 6 wires in the following colors; orange, violet (purple), red, black with a green stripe, green, white. This module is a big hunk of metal and you will need to consider where you will locate it.
Remove your ignition coil (if you remove any connectors note their location, there is a (+) and a (-) side on the coil connectors. Bolted to the mounting bracket along with the coil is a metal plate with the Land Rover control module attached "the assembly". There are two wires (blue and red) running through a connector on "the assembly". Detach the connector. There are two additional wires running from a black connector on the control module "assembly" to the coil. The white with black stripe connects to the negative side of the coil, The white wire connects to the positive side of the coil. Disconnect these two wires at the coil.
You should now be able to remove "the assembly" from the rover. "The assembly" is a metal bracket onto which is bolted the Land Rover control module; a connector with a blue, a red and a black (ground) wire; and another connector from which a white with black stripe wire and a white wire will be dangling.
On "the assembly" cut the red wire, the blue wire and unbolt the black ground wire. This will enable you to remove one connector from "the assembly". You will solder this connector onto the Ford Duraspark so leave enough wire to do the soldering. I chose to cut the black ground wire off of the connector as I didn't see a use for it.
I solder all connections and shrink wrap them for insulation. You should too.
1. Now solder the blue wire from the connector to the orange wire on the Ford Duraspark.
2. Solder the red wire from the connector to the violet(purple) wire on the Ford Duraspark.
By reusing the connector and wires you will be able to plug directly into your wiring loom.
3. Solder a length of black wire onto the black with green stripe wire on the Ford Duraspark. At the end solder a connector with a round hole. This is the ground and you will ground it to one of the bolts holding the coil.
Back at "the assembly" remember the white with black stripe wire and the white wire that you left dangling? Now you need to cut the connectors, that connected to the coil, off of those wires. Note which connector goes to which wire as they are different (one is male and the other is female. Keep them seperated as they aren't nutered and we don't need any little unwanted connectors coming out of their union.).
4. Solder a length of red wire onto the red wire on the Ford Duraspark. Solder the connector from the white wire (+ positive side) to the end of the red wire.
5. Solder a length of green wire onto the green wire on the Ford Duraspark. Solder the connector from the white with black stripe (- negative side) to the end of the green wire.
6. I did nothing with the white wire. Toddco notes that you can connect it to the solenoid on the starter for easier starting. Something about retards the timing while starting. I simply wrapped the end of the wire with insulation to prevent shorting.
Those added lengths of wire are variable depending on where you decide to mount the Ford Duraspark.
Now, put it all back together. On one of the mounting bolts where the coil will mount there should be a grounding strap. On that same bolt there should be a ground wire from the loom that contains the other end of the blue/red wire connector. Add the ground wire from the Ford Duraspark and remount the coil. There will also be a small cylinder that mounts with the coil too. (This is just the way it was prior to disassembly except that "the assembly" is now gone and you are adding the ground from the Ford Duraspark.)
Connect the red/blue wire connector from the Ford Duraspark to the corresponding red/blue wire connector in the loom.
Connect the Red wire from the Ford Duraspark to the positive side of the coil.
Connect the Green wire from the Ford Duraspark to the negative side of the coil.
Toddco, notes the following: "Please notice the changes. The Duraspark box fires on the rising edge of the signal. If your Land Rover original box fired on the falling edge then the polarity will be reversed, meaning blue goes to orange and red goes to violet(purple). Be sure to check timing when finished!"
My note to Toddco's note: It seems that he meant to type, in this note, "... will be reversed, meaning blue goes to violet(purple) and red goes to orange. ..." . My Rover cranked right up so I assume that I did everything correctly. As you read above in my Defender it is blue to orange and red to violet(purple).
Check your work! Start the Rover! Check the timing!
How to check timing from ???
"... Find the mark for 5 deg. BTDC on the bell housing, connect the timing light, turn engine on and turned distributor until 5 deg. mark and the mark on the block line up."
My notes on timing. On other cars, I'm used to lining up a notch on a pulley wheel with a corresponding mark on the engine block. The Defender is pretty cool in that there is a gauge etched into the "pulley wheel". The gauge goes from 12 degrees BTDC (before top dead center) to 12 degrees ATDC (after top dead center). If you get under the rover and look at the pulley closest to the block you'll see this gauge. (You might have to crank (don't start) the engine to get the gauge to rotate to the bottom). Back up and looking from the top of the engine you'll see a fin molded into the engine block at TDC. Shine the timing light from above and set the timing as desired. (5 deg BTDC ???)
Attached is a picture of the Ford ICM mounted. I took some aluminum sheet probably 1/16 of an inch (fairly stout) and cut it to mount under the left wing. I bent the ends of the sheet so that when bolted to the galvanized wheel well the mounted Ford module sits parallel to the ground and the fender above. I also mounted the coil and one of the horns on the aluminum sheet. This was to tidy up the installation.
This installation is easily reversible except for the 3 holes drilled in the wheel well.
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