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Toyota COP
mini-sprite - 28/11/15 at 10:08 PM

I'm switching from wasted spark and a coil pack to individual COP. I have 4 coils from a Toyota (4 wire see photo)





I'm using megasquirt and have a loom supplied by the guy who built the megasquirt. In the loom there are 2 spark output wire labeled A & B. I was expecting to wire them like this for sequential firing.



It doesn't seem possible with the loom i have. I can add the extra wires myself but if i use it as is, it would be wasted spark COP?

Paul

britishtrident - 29/11/15 at 05:45 AM

On 3 and 4 wire COO the switching transistor is in the COP
On a 3 wire system the connections are power, permanent ground and the control wire which Toyota call IGT. (Ignition Timing)
The 4th wire on Toyotas is IGF for ignition confirmation by the Toyota ECU continuous monitors.

Power, Ground and IGF are common between the COPs.
IGT is individual to each COP on most systems I have worked on it is green+colour
IGF is normally the yellow pin 2

The IGT is normally square wave 0 to 4 volts, the coil fires when it falls to 0 volts.

mini-sprite - 29/11/15 at 08:22 AM

quote:
Originally posted by britishtrident
On 3 and 4 wire COO the switching transistor is in the COP
On a 3 wire system the connections are power, permanent ground and the control wire which Toyota call IGT. (Ignition Timing)
The 4th wire on Toyotas is IGF for ignition confirmation by the Toyota ECU continuous monitors.

Power, Ground and IGF are common between the COPs.
IGT is individual to each COP on most systems I have worked on it is green+colour
IGF is normally the yellow pin 2

The IGT is normally square wave 0 to 4 volts, the coil fires when it falls to 0 volts.


So really if IGT is individual these are the wires that would go to spark ABCD in the loom to the megasquirt? Which is my initial head scratcher as the loom only indicates spark A and B. This would suggest that although the megasquirt has 4 coil drivers it is

1. 4cy Semi-Seq Fuel & Wasted Spark with 4 coils (COP)

and not

2. 4cy semi Seq Fuel and Seqential COP (Coil on Plug) Ignition

I would prefer to run with option 2 as i plan to turbo at a later date (once i get enough signatures to upgrade my race licence) i might as well just run a Bosch coil pack in wasted spark as i had on my last redtop engined racer.

Paul

britishtrident - 29/11/15 at 08:30 AM

Of course it would be much simpler to use 2 wire waster spark as per BMW & Rover kv6
Personally I have never found wasted spark a problem even wasted spark cop.

mini-sprite - 29/11/15 at 08:48 AM

COP wasted spark it is then.....that kind of simplifies it which is good as i understand that

Paul

mini-sprite - 30/11/15 at 08:26 PM

http://www.sq-engineering.com/tech-articles/coilpack-info-guide

if i'm understanding it right pin 3 IGN would not be needed for megasquirt?

britishtrident - 30/11/15 at 09:34 PM

IGF is an output to the ecu purely for fault monitoring. Not required.

The problem is 3 and 4 wire coils are driven by a 4 to 5 volt square wave input on IGT which switches a transistor built into the coil , istr the magnetic field builds when the square wave goes high and fires when the square wave drops to zero.
Normal coils and 2 wire coil packs have a continuous 12v supply shared by all coils on the engine the coil is charged when the individual coil negative is connected to earth and the spark fires when the earth circuit is cut.

[Edited on 30/11/15 by britishtrident]