Megasquirt Support Forum (MSEXTRA)

Hi guys,


Real weird one here, I have been running quite happily a pair of NGK 48038's which compare too the following:-

SKODA (06A 905 097)
SKODA (06A 905 097 A)
SKODA (06A 905 104)
VW (06A 905 097)
VW (06A 905 097 A)
VW (06A 905 104)~

See page 101 of the MS3X/V3.57 Hardware Manual


One of the original NGK coils lost a channel (tested via can bus mode tests and substitution)

Now due purely to timescales of availability I have just tried a HAAS 41344031( and also a another as assumed new part was DOA) and they appear to be dead as a dodo.

I tried swapping the existing good one to the opposite bank that works, and the new HAAS one to working NGK side, the NGK still works , but the HAAS is still dead?

I'm driving the coils from the MSX logic drivers in full sequential mode , one channel per spark output.

I'm really scratching my head here , as cant work out why these dont work , when they should be exactly the same part.


The only difference I can find is the NGK ones state "with output stage" , whilst all the others state "Coupling Type Saw Tooth"


But even the engine codes from the original parts are the same :-

NGK Coil, ignition 48038 6terminalIgnition Coil SKODA OCTAVIA Combi (1U5) 2.0 from Year 04.1999 116 PS: Coil, ignition (48038) for from NGK
8.4/10 Reviews - 5
Article №: 48038
NGK Coil, ignition 6terminal

SKODA OCTAVIA Combi (1U5) 2.0 from Year 04.1999 116 PS
Number of Poles:6
Engine Code:AZJ
Required quantity:1
Ignition Coil:with output stage
Port Type:M4
Number of Inlets / Outlets:4

BERU Coil, ignition 0040102029Ignition Coil SKODA OCTAVIA Combi (1U5) 2.0 from Year 04.1999 116 PS: Coil, ignition (0040102029) for from BERU
8.7/10 Reviews - 3
Article №: 0040102029 (this is recommended from h/w maual)
BERU Coil, ignition

SKODA OCTAVIA Combi (1U5) 2.0 from Year 04.1999 116 PS
Engine Code:AZJ
Required quantity:1
Ignition Coil:Coupling Type Saw Tooth


and my new one:-
HAAS Ignition CoilProduct Code: 413440431
Ignition CoilCoupling Type Saw ToothRequired quantity1Engine Code AZJ



Has anybody else hit issues like this, and is there any change in config settings that may help this ?


Fortunately I have a pair of the BERU coils coming next , but really worried these wont work either?

I just looked further down the pages in the manual and see:-

"Before using an "unknown" coil it is necessary to check the resistance to ground on the input.
Using a multimeter set to resistance, check between the Spark Signal Input and Signal Ground.
If you have a reading of say ~1k then the Megasquirt MS3X outputs can be used directly"


Interestingly the new coil pack signal gnd -> signal input are 500 ohms , comapred to the NGK working ones which are 1k.

Are the new coils simply sinking too much current for the MSX drivers ?

I hooked up a simple test rig, where substituting resistors , I was able to determine the firing point for each of the coils, and low and behold, the HAAS ones need twice the amount of current :-


HAAS
Logic level +5v current limit set @ 16mA- NOT FIRING!!

Logic level +5v current limit set@ 25mA Fires

NGK

Logic Level +5v unable to determine bottom end limit, but fires as low as 2.5mA .

If this is the case for the new BERU coils arriving I'm in deep doodoo

It looks like if I want to allow for OEM coils, I need to cover all bases, and add some additional drivers to the logic outputs from the MSX.

I have found a few mentions of this, but as by nature of the forums , nobody has published a circuit diagram, and what components to use.

I'm running full sequential of the MSX card, I dont want to go wasted spark due to the messy coil HT leads crossovers , so just want something in series to give the outputs a "boost"


Ideas anybody?

Use the TC4427 circuit externally driven by the MS3X.

James

James,

Thanks, that's exactly what i was after , I assume you mean the subject of this thread:-

http://www.msextra.com/forums/viewtopic ... 31&t=58469


and Page 90 of the MS3 h/w manual.

The only issue i guess will be the decision on wiring, I guess I can pull the 5V from proto on the ECU and wire through the DB15 connector , and then use that to power an external module PCB, and then simply place the new module in series with the existing spark output wires.

As I need 8 logic outputs I still require the need to use the MSX, so taking these directly off the msx board wont be easy, apart fro using the external existing db37.

Otherwise I could place the new module nearer the coils using the 12v supply off those , to power the module.?



I think the former would be less likely to suffer any interference.


Thanks..

James,

One more question, as the input resistance e is somewhere between low and high impedance Logic coils , will that govern the size of the resistor value to use, which was quoted as 15R 1/8W, I assume with a coilpack of around 600R , I may need a higher value resistor?

regards..

The specified values should be ok.

James

James,

Thanks, I'll hook it up this week, and update the post.

Regards..

Rob.

I'm closing this post down with the final outcome, as it drives me mad when people don't!


My new BERU coils arrived, stamped with the official part numbers:-

0040102029, 06A905097

I thought I'd test these out first, and initially using the low current as per the original NGK coils they did not work, however giving a little more current @7-8mA they fired !!!

This is well inside what the ECU can drive, so happy they should always fire, plus a little more protection of misfiring.

I have now fitted them, replacing both the NGK units (keeping the good as a hot spare), and have been working faultlessly for the past 2 weeks .

Thanks James , for the alternative solution, but as I now have a proven solution, I'm sticking with it.

Regards


Rob.