I'm reproducing the Nicoclub information, and rehosting imaqes on our server, just in case.
GM Ignition Swap - (CA18DET)
What does this do?
1. Eliminate need for COP and Nissan ignitor
2. Convert ignition to GM waste spark DIS
3. Coils last longer from cooler operation and are cheaper, easier to get
4. Ignitor is readily available new and used
5. Hot ignition spark (modified dwell map)
6. Easier to check your timing with timing light/gun (no special tools or rigging required)
7. Cleaner possible emission from waste spark
8. Easier to maintain
9. Improved aesthetics, no need to run without the coil cover
Important Requirements
- Soldering knowledge or basic wiring skills
- Socketed ECU
- eprom optional but recommended
- NGK spark plugs gapped 0.7mm (0.028")
Terms used:
- PnP (Plug and Play)
- COP (Coil on plug)
- OEM (Original Equipment Manufacturer)
- DIS (Digital Ignition System)
- GM (General Motors)
Tools Needed (incl. a phillips head screw driver):
Hardware and GM Ignition Parts used:
- GM Harness pigtails
- GM Coils
- GM Ignitor
- Mounting hardware
____________________________________________ ___________________________
Building the PnP Harness:
I raided the local junk yard to find a Nissan or Infiniti with the 2 Male plug ends needed to make this harness.
Parts List:
- 2 x 6 pin male connectors
- 4 x 1N914 high speed switching diodes
- radio shack pre-drilled board (optional)
- High temperature electrical tape
- 1 x GM ignitor power pigtail
- 1 x GM ignitor trigger pigtail
- crimp on round connector with 6mm (0.25") hole
PnP harness wires:
Step 1:
Start by soldering the (4) 24" wires, diodes and (2) 8" wires together. I used a pre-drilled board from radio shack to complete this part:
Step 2:
Connect the 4 free ends on the 24" wire to the male oem connector as in the diagram (right plug). Match up the ignition 1 - 4 wires as labeled in the diode pic above with the appropriate signal connection on the male plug. The red power wire can also be connected with the other male plug (left plug). This is the only wire used from this plug to provide the switched 12V for the GM ignitor. The other end of the 12V wire goes to the matching pinout on the GM ignitor power pigtail. Crimp the circle "eye" connector onto the ground wire and the other end to the matching ground on the GM ignitor pigtail:
** Completed Plug and Play Harness **
Pre-Install Requirements:
- Remove the Coil plug cover
- Remove OEM COP setup including the coils and harness
- Install the spark plug wires. I used wires for a 94 Cavalier. Although the 7mm wires work, try to upgrade to a 8mm wire.
- Label the spark plug wires 1,2,3,4
- Replace the coil plug cover
Mounting and Installing the GM Ignition
Try to locate the Coils and ignitor somewhere in the engine bay that would allow convection cooling of the coils. I chose either of two methods using custom aluminum mounts:
Mounting Brackets
1. - Mount the GM coils and ignitor in a front mount configuration
The following are required:
- Front aluminum plate/ heat sink, grounded
- Electric fans
- Modify the coil cover by removing 3/8" from the front of the coil cover
PROS:
Cooler operation
Easier access
Lots of space
Cooler than oem coil operation
CONS:
Longer spark plug wires required compared to top mount setup
2. - Mount the GM Coils and Ignitor in a top mount configuration
The following is required
- top mount aluminum plate/ heat sink, grounded
PROS:
Shorter spark plug wires compared to front mount
Cooler than oem coil operation
CONS:
Coil runs a bit hotter compared to the front mount configuration
Plug in the custom PnP Harness
- Plug in the GM end of the harness to the Ignitor
- Plug in the shorter 6 pin male PnP plug for the 12V switched power to the ca18det EFI harness female connector where the OEM COP harness originally connected. Connect the ground wire of the PnP harness with the crimped on connector to the EFI harness ground on the side of the intake manifold.
- Disconnect the bigger 6 pin female connector from the OEM ignitor. The other plug can be removed as well since the oem ignitor is no longer needed in the engine bay. Basically up to you.
- Plug in the other longer 6 pin male plug on the PnP harness to the 6 pin female connector on the OEM EFI harness. For euro models S13, this connector is part of the main harness but essentially the same plug.
Check all your connections
Start the car - The engine should idle and rev normally under no load
Dwell Map modification
In order for the coils to function properly the following changes MUST be made to the dwell map on the EPROM. You can use ECUEdit to make this change or if you're using romedit, you can setup one of the additional maps with the hex location for the dwell map. These settings provide a nice hot spark while still maintaining cool coil operation. I've tested the spark to 15psi with no breaking up with my GT3071R turbo. 20psi should be more than capable for this setup without blowing out the spark.
the ca18det dwell map is located at H3890 and is 32bits long
Article courtesy of 50-50 from http://www.nicoclub.com
There are easier ways for those that don't posess the equipment or know-how to re-map an ECU.
Found this kicking around on the interwebs (Does not require any ECU or ignitor mods):
After market coils for CA18DE-T multicoil (U12, S13)
N/A for U11 motor unless later model ECU and loom from s13 or U12 is upgraded as well.
Parts: (stuff to buy)
4 X Bosch coils HEC-715/6 (diffence in lead connector on coil, male/female) about $40 - $60 per coil
1 X Custom lead set, about $120 - $150 for a decent 10mm set.
1 x Bracket to mount coils - can be any $ depending on who you know and how fancy it is, ie: mine was
free, but i had to drill holes myself, material and bending was free.
8 x Female spade connectors (larger size of the two available) for wiring - $5
1 x 6 pack of fav alchol
Tools: (stuff to borrow)
wire strippers
crimpers / wire cutters
Intructions:
First thing would be to get your bracket made up for mounting the coils onto, and also while the car
is still running with the stock setup, take it to your local leads place, and show them where your
coilswill be sitting so they can make up/give you the correct length set for your application and
still drive your car home. This way you will have all you parts ready to go and knock the job over
all at once.
Disconnect the negative terminal on the battery. Take the coil cover off of your motor, 8 bolts
10mm/phillips (NB: If you have your top mount still installed remove this first, which is pretty
straight forward, just look for the bolts and clamps holding it on). Begind drinking your 6 pack. Disconnect the wiring from
each coil marking each plug/connector as you go with a number corresponding to which coil you pulled
it off of - number 1 is closest to the timing belt (drivers side/right side) and continues upto 4
consecutively to the other end.
Sell your stock coils to someone along with all the bracketing. Mark each of your new coils with
numbers from 1 to 4. You should probably have your coils mounted on your bracketing system and worked
out where the bracket will sit in your engine bay by this stage so you can work out how long your new
leads will have to be, and also how short you can cut the old wiring to hook up to your new coils, or
even how far you have to extend your wiring depending on where you decide to put the coils, closer to
the plugs is prolly better for tidyness, not on top, just close.
The new coils will only have a + and -, where as the old factory coils had three
wires. The thin black wire can be disgarded completely, follow where it goes and remove it. The
thick yellow one is constant remote power (+) which is a common for the coils and the pink one is
the trigger/negative (-) which has an INDIVIDUAL signal for each coil. Connect each yellow wire
to each coil on the + terminal, and the pink TO THE CORRESPONDING coil - ie: when you disconnected
the wiring connectors/plugs from the stock coils and marked them with numbers, connect the pink wire
from the connector marked (1) to the aftermarket coil you have marked (1) onto the (-) terminal and
repeat so on until (4). * When you cut the each of the wires from the standard plugs, strip the end of
the wire, and crimp one of your spade connectors onto the wire, then plug it onto the correct terminal
on the coil. Don't cut all the wires from all of the standard plugs at once, or you won't know which
is which, just cut one wire at a time and connect it the the correct coil straight away to avoid \
confusion later on, especially if you enjoying a few rumbos while you work Tape up all your wiring
etc, tidy it up, put condue on it if you like, make it look pretty.
Plug the leads onto your coils and then to your spark pulgs, once again marking sure the lead coming
from your new aftermarket coil marked (1) is going to number (1) spark plug, which once again is the
one closest to the timing belt/drivers side of the motor. Repeating up until number (4) continuing
to the right sequentially.
Just curious.....how much truth is there to the factory ca coils actually crapping out from too much heat? I kinda find this hard to believe, as my maxima has the same style coil pack design, and they've got just under 190k miles on them, and I've yet to have an issue with any of the 6.
Just wondering....I've see this Nico write-up before...good stuff
I don't think it's always heat-related. Most of the time, it's due to moisture entry, and poor maitainance.
As you said Keith, there's no reason why they can't go 190K miles without hassle.
Umai NaaI don't think it's always heat-related. Most of the time, it's due to moisture entry, and poor maitainance.And age.......
Umai Naa @ Aug 22 2008, 03:22 PM
I don't think it's always heat-related. Most of the time, it's due to moisture entry, and poor maitainance.
alot of j30 chassis max's the VE30DE ones they tend to crack all the ones i see at the junkyard are most always cracked
EightySix200SXalot of j30 chassis max's the VE30DE ones they tend to crack all the ones i see at the junkyard are most always crackedYou mean vq30?
EightySix200SX @ Aug 25 2008, 09:11 PM
alot of j30 chassis max's the VE30DE ones they tend to crack all the ones i see at the junkyard are most always cracked