NON ZR-1 Technical Help needed

[limey]

Originally Posted by scottfab

Very interesting indeed. I've noticed two design elements obfuscated into the schematic which explain why shorting 2 to 4 on the four wire design does not work.
Since this is not a ZR-1 issue for a donation to the club I would consult on the what's going on. Certainly the cost could be passed on to the owner of such a fine automobile.

I have no problem with this at all, I'll donate $500.00 to the club if what you tell me works and show us how to implement it. I've spent countless hours and resources on this, so money well spent. Mind you, if your solution doesn't work, no money donation, sound fare?

Bill, will get with you on this tomorrow, will need to look into this.

[scottfab]

Originally Posted by limey

I have no problem with this at all, I'll donate $500.00 to the club if what you tell me works and show us how to implement it. I've spent countless hours and resources on this, so money well spent. Mind you, if your solution doesn't work, no money donation, sound fare?

Bill, will get with you on this tomorrow, will need to look into this.

Kurt, Good enough, does Bill have an email address?
I can walk him through a bench test then wiring changes.

[limey]

Scott,

Can you pm, or call me with the info. Once confirmed that this is successful, I will paypal $500.00 to the registry.

Kurt.

[scottfab]

Kurt, I will call later on today but be aware. The bench test (or putting the coils into another car) will be needed first to verify component viability. If they were wired wrong initially the internal transistor could have been fried.

From there a few "on car" measurements will be needed the a "where to cut" process. Does the car run at all with the old coils? If so that speeds up the mod.

[limey]

Car is in house and all tests can be confirmed. I have lots of coils :-)

[scottfab]

OK Kurt, Here is what I've found.
To start with the pdf schematics for the 2002 and 2004 are more of a logical diagrams and do not contain all actual specifics of the circuit.

Having said that and after examining both coils I now know enough to say the 2004 circuit uses a positive transition pulse to turn the coil (create HV at the output).
The 2002 circuit uses a negative going pulse to do the same.
An example here shows what the two look like. First is the 2004 pulse
the second is the 2002 pulse.


What does this all mean? It means just changing the wires in the harness and shorting pin 2 to pin 4 will not work.
What has to happen is an inversion of the pulse on each coil input from the ECM.
This can be done by adding a transistor (and possibly other protective components) to each coil. I can furnish a rough schematic of this.
Sorry I know this is not what you were hoping.

BTW the output voltage of the 2004 coil is MUCH greater than the 2002 coils.

[XfireZ51]

Scott,

I think what you have discovered is very similar to what we did in adapting the LSx coils on the LT-5. In our case, we converted what was grounding the coil by the Ignition Module into a triggering signal. The signal was ~.4v and it was inverted.

Originally Posted by scottfab

OK Kurt, Here is what I've found.
To start with the pdf schematics for the 2002 and 2004 are more of a logical diagrams and do not contain all actual specifics of the circuit.

Having said that and after examining both coils I now know enough to say the 2004 circuit uses a positive transition pulse to turn the coil (create HV at the output).
The 2002 circuit uses a negative going pulse to do the same.
An example here shows what the two look like. First is the 2004 pulse
the second is the 2002 pulse.


What does this all mean? It means just changing the wires in the harness and shorting pin 2 to pin 4 will not work.
What has to happen is an inversion of the pulse on each coil input from the ECM.
This can be done by adding a transistor (and possibly other protective components) to each coil. I can furnish a rough schematic of this.
Sorry I know this is not what you were hoping.

BTW the output voltage of the 2004 coil is MUCH greater than the 2002 coils.

[XfireZ51]

Oh 1 other point. The LSx coils required a 20A power circuit for each side.
Ran that direct from battery w relays for switching ON. Think I still have the harness for that.

[scottfab]

Originally Posted by XfireZ51

Oh 1 other point. The LSx coils required a 20A power circuit for each side.
Ran that direct from battery w relays for switching ON. Think I still have the harness for that.

That must look pretty interesting. I think in this case it should be possible to invert the signal directly and to do it with as few noticeable appendages as possible. There are 12 coils and the wiring is already set up for individual coil driving. The current load is easily handled by the existing wire size. The fuse may need to get bigger.
We'll see.

[XfireZ51]

The wiring is the in the LT-5 also but it uses a 10A circuit for the coils.
As you have already noted the VW coils are much more powerful than the 2002 coils. That takes more power. Is the 2002 circuit up to it?