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Working with Coilpacks

This article is about use of coilpacks also known as COP's (Coil on Plugs) which are common on many Toyota engines.


The bulk of the information and the first picture on this site where courtesy to Anthony Kellam





Coilpack basics:

Just about all of the new Toyota engines use a coil-pack for ignition. Where previously a single/double engine bay mounted coil was used with a distributor or external coils for pairs of cylinders coilpacks are an all in one solution for each spark plug. The are a very compact ignition coil which is designed to fit directly onto the end of the spark plug.




Toyota Coilpack Types:

20V VVT disassembly

Coil 1: 90919-02227 ST215 Caldina 3SGTE

Coil 2: 90919-02230 GXE10 Altezza AS200/Lexus IS200 1GFE vvt-i

Coil 3: 90919-02239 ZZE120 Corolla 1ZZFE

Coil 4: 90919-02240 NZE121 Corolla 1NZFE

Coil 5: 90919-02236 SXE10 Altezza RS200 3SGE Beams dual vvt-i


Not pictured are 2AZFE Camry and 2NZFE. Both of these are longer types, which are useful when some extra reach is needed. Similar in length to the GXE10 (2) coils pictured above.




Fitment of coilpacks to a 20V engine:

The inside diameters of the spark plug tubes on a 20V engine are 24mm, unfortunately the outside diameter of the most compatible coils are close to 24.4mm at their highest. So to make them fit the cols needs to be machined/shaved down to suit. This can be done crudely with a file or at best in a lathe using a 4 jaw chuck and a great deal of care. Also to note if these are to be machined use a high speed steep cutter that goes to a very sharp pointed tip and with no radiused edge. Below shows an unmodified coil on the left and a coil that has been machined in a lathe on the right, both are from a 1NZ engine.

  

By far the best fitment for  a 20V engine is a 1NZ coil as above. This is shown here installed on the right, to the left is a 1ZZ coil. The space from the cam cover to the bottom of the clamp on the coil for a 1NZ coil is 8mm, for the 1ZZ coil it is greater. It is reported a silvertop cam cover can be fitted over 1NZ coils if correctly positioned, although it does raise the question of adequate coil cooling when under a well fitting cover.

 





Electrical Connection:

Unlike other companies coils which more commonly have just use an encased coil with a twin wire connection all Toyota coils have an inbuilt igniter.  This means they can be run directly off the ECU's ignition output without any ill effect. The tell-tale sign of an coil with an inbuilt igniter is a 4 wire connection instead of 2. The pin connection for almost all Toyota coils is shown as below:




Pin 1- Earth: Constant ground, join all the coils together and ground to the body, grounding to the cam cover is not suggested at all.

Pin 2- IGT: Ignition triggor, this is the signal wire to activate the internal igniter, it can be connected directly off the output of any ECU even with multiple coils in parallel.

Pin 3- IGF:  Ignition feedback, after the coil fires this pin sends a confirmation of firing. Not needed for any aftermarket ECU, however if not connected on a factory ECU it will go into a fault mode. For 20V owners using the OEM ECU the                             signal from only one coil (any coil) is needed to go back to the ECU.

Pin 4- +V: Switched power, power feed switched when ignition is on. The easiest and likely the best way is to just use the power feed from the original coil and then power all four of the new coils instead.




Mounting:

As shown in the previous pictures all of the Toyota coils are secured via the use of a single mounting tab. To adapt this to other engines it can through various forms such as an adapter plate, bosses welded to the cam cover or even the friction of the coils in the tube.

Shown is an adapter plate from the parts section that is now available. It's bolted to the middle of the cam cover of either 20V engines. It uses the three blind threaded holes originally used for the spark plug lead clips.  For more information please see here: 20V Coil-pack/COP Adapter plates: