Converting to Coil on Plug setup

[iblackwood]

Hi,

Please be gentle - MoTec is new to me. I don't think I am treading new ground here though, so I hope those more knowledgeable can assist me !

I have an M4 Clubman ECU for fitment to a Toyota 4AGE 20 valve Blacktop.

The M4 is setup to use:
Toyota distributor for Sync and Ref
Single igniter / coil with the distributor cap doing the HT distribution.
MAP Sensor and Ford Idle Control Valve
Toyota's injectors and TPS that came with the motor.
Auxilary outputs are used for 1- VVT actuation, 2 - Thermo-fan, 3 - ICV, 4 - Fuel pump
Existing map to suit above.
Note: All Auxilary outputs are currently in use.
Note: Finance minister would baulk at buying an IEX.

I am looking at fitting Toyota 1NZFE Coil on Plug coils which have a built in igniter. As I just about to pay for a wiring loom, it becomes decision time !

My intention is:

1. Free up an Auxiliary output currently assigned to the thermo-fan (I will put it back on a thermo-switch)
2. Reassign the functions on the auxilaries so that AUX2 is free (I realise this is probably not technically required)
2. Reassign the Aux2 Output as IGN2
3. Set the number of coils to "2" and wire the ECU outputs to the "IGT" trigger inputs on two coils each paired so they "wasted spark" on the exhaust stroke of the "other" cylinder.
4. Set Dwell on the coils to 2.5ms (assuming they are similar to the Daihatsu coils)


My questions are:
1. Sanity check please !
2. Is it easy to change / move the functions of the Auxilary outputs around ? Will I need to define them from scratch ?
3. Will the mapping need major rework - or will it be just a few percent different ? i.e. will the ECU provide the existing map correctly despite the change in coil numbers ?
4. Is it okay to drive the CoPs (inbuilt igniters) direct from the ECU and/or will I require shielded cable for these connections ?
5. How would I drive a VDO tach in this arrangement (the Toyota CoPs also have a IGF feedback signal) ? I realise this question is slightly out of MoTeC scope, but am open to input from those more experienced (grovel, grovel).

Sorry for the long post, hope it all makes sense.

Thanks in Advance to any responses !

Ian B

[AdamW]

It looks like you will be cutting it fine with all of your aux outs tied up. Yes can put the fan back to a standalone thermoswitch to free up one output, but it would be nice to free up another which you could then assign as a tacho signal. The outputs are quite easy to change around, just make sure you save a copy of your current map before you go making changes - then you've got something to refer back to (and copy from) if you need to look at how the idle valve was previously set up for example.
If you cant free up another ouput for a tacho then you have a couple of options:
1. a tacho adapter/ignition combiner - this takes the signal from each coil and combines it into a tacho signal. Motec make one and you can also find them on some OEM wasted spark cars, mistubishi lancers for example. I think you can do it DIY also with a couple of diodes.
2. An IEX. I know you said the finance wont stretch that far but they're fairly low cost - I've seen them on ebay for about USD200.

In any case, the motec will drive those coils with built in ignitors fine and will work perfectly well in wasted spark mode. They are quite decent coils too - they seem to be reliable and give a good spark.
The cables donot need to be shielded.
The dwell setting in motec is quoted at 15V so you should probably use something more like 2.2ms for these coils.
You should not normally need to change any of the map at all - in my experience unless the car had some problem like a misfire with the old ignition then an ignition upgrade will not change the tune significantly if at all.

[AdamW]

Have a look here for a DIY tacho combiner:
http://www.mrm-racing.se/forum/showthread.php?t=675
Note, I have never tried one like this so you're on your own.

[Holmz]

Hi,
...
My questions are:
...
4. Is it okay to drive the CoPs (inbuilt igniters) direct from the ECU and/or will I require shielded cable for these connections ?
...

Ian,

I think that you better check to make sure the COP need or do not need a driver.
I was told that they do, so I got an Audi amplifier (coil driver).

Bosch parts email...
Ignition Module, part # 0 227 100 211, cost $162.72 plus shipping is available.
(I got a used one off of ebay from an Audi for ~40 UD$)

This ignition module does not come from Bosch with the heat sink paste and installation screws and washers. We have a kit containing these items sufficient for 1 module, your cost $1.15. (part # B 227 003 035).

We also have available the heat sink, part # B 221 040 009, your cost $19.74.

[AdamW]

Holmz,
The 1NZFE is basically the same coil as the 1zz & 2zz, just different lengths. They are all 4 wire denso's with built in ignitors. I have personally used these coils on many engines.
There's already another couple of posts on this forum too:
viewtopic.php?f=19&t=1858
http://www.motec.com.au/forum/viewtopic ... 666&p=7570

[Holmz]

Holmz,
The 1NZFE is basically the same coil as the 1zz & 2zz, just different lengths. They are all 4 wire denso's with built in ignitors. I have personally used these coils on many engines.
There's already another couple of posts on this forum too:
http://motec.com.au/forum/viewtopic.php?f=19&t=1858
viewtopic.php?f=11&t=1666&p=7570

OK
The ones I got (Different engine) did NOT have the ignitors built in.
I hear it is gets expensive when that type is run on an ECU trying to sink huge current.

[iblackwood]

Hi,

Thanks for the responses.

Yes, these particular CoPs defintely have inbuilt igniters. Yes, sinking a coil directly would be a bad thing.

Thanks for the link and the dwell figure Adam, but I would need to login to see the diagram. Fortunately it appears the IGF signal (normally used to signal successful firing to the ECU) is an open collector setup that turns on after the coil fires. So it would seem if I take an IGF from one of each pair (wasted spark remember) to my tacho and then at the tacho end supply +Batt via a 1K resistor on the connection at the rear of the instrument that I should have a working tach without making things messy or looking like a science experiment. I'll confirm the IGF signalling when I get the CoPs as it should be pretty simple to test out of car.

I have a telecommunications / electronics background and centrally run a statewide IT network. You bet I'll have backups of the ECU settings for each change !

I consider not having any spare auxilaries means I got my money's worth. Of course if do see an IEX going cheap...

This thread is still open to passing wisdom....

Cheers
Ian