COP...................

[Donal]

No not that sort! Has anyone tried using a Coil on Plug system?

https://delphi.com/manufacturers/auto/power...gnsys/igncoils/

Has anyone fitted one to an FJR?

Extract from Wikipedia:

Modern ignition systems

In modern systems, the distributor is omitted and ignition is instead electronically controlled. Much smaller coils are used with one coil for each spark plug or one coil serving two spark plugs (for example two coils in a four-cylinder engine, or three coils in a six-cylinder engine). A large ignition coil puts out about 20 kv, and a small one such as from a lawn mower puts out about 15 kv. These coils may be remotely mounted or they may be placed on top of the spark plug (coil-on-plug or Direct Ignition). Where one coil serves two spark plugs (in two cylinders), it is through the "wasted spark" system. In this arrangement the coil generates two sparks per cycle to both cylinders. The fuel in the cylinder that is nearing the end of its compression stroke is ignited, whereas the spark in its companion that is nearing the end of its exhaust stroke has no effect. The wasted spark system is more reliable than a single coil system with a distributor and cheaper than coil-on-plug.

Don

PS thought I'd better get this in before Friday!

 

[Geezer]

I have a couple vehicles that use coil on plug. It works great. The coils are very expensive when they need to be replaced.

 

[Afast03nNJ]

Coil On Plug in my Nissan Maxima VQ motor.

 

[Fred W]

Unfortunately, because the FJR's ECU only has two coil trigger outputs, even if one were to convert the HV part of the ignition to C.O.P., it would still run as a "wasted spark" system i.e. two plugs would still always fire together, even though only one is at the ignition point between intake and power strokes.

There would be several advantages to the conversion though. There would no longer be any need for plug wires and boots. Each plug having it's own HV source would result in a hotter spark. It would also mean that the potential (voltage) applied to each plug was of the same polarity (ideally negative) so that the spark would always jump from the center to the side electrode, rather than having half the plugs fire in reverse. Then we might actual realize the full potential life of the iridium center electrode plugs that people are so fond of paying extra for.

The main problem in the conversion would be in fitting the coils into the space over the plugs. Not sure that they would fit under the bottom of the tank. There also may be an issue with finding coils whose sum (of two) impedances on the primary side is similar to the FJR coil's. That may make the ECU unhappy and throw error codes, etc.

But maybe...

 

[Donal]

Thanks for the input guys. Plenty of 'food for thought' there especially Fred's comments. I guess I need to spend a bit more time thinking/researching! :blink:

Don