Best place to take electrical reading from injector and how...

VAG-Slag

VAG-Slag

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My WMI controller takes a duty cycle reading from the injectors and mirrors that for it's own injector solenoid...

Where's the best place for me to tap into the injector wiring and how? Would be good if I could to it at the injectors I suppose but what's the best way to tap into that without f*cking sh!t up!?

For reference here's the wiring diagram for the kit:
http://howertonengineering.com/wp-content/gallery/legacy-systems/instruction.png

Any advice appreciated, thanks!
 
So on lack of advice I decided to have a crack and f*cking sh!t up like I know how and all was going strangely well... Spliced and soldered:


And then insulated:


Was a bit confused that everything went so well so in typical man style I read the instructions after doing stuff where it says:

"great care must be taken that the red wire must be connected to the non-switched side of the injector driving wire. If there is an inline power resistor please splice red wire to the ECU side of the driving wire. The green wire splices into the pulsed or the side of the injector driving wire"

Can someone please confirm for me that there is an "inline power resistor" and that I have indeed successfully f*cked sh!t up?
 
audi upgrades
From memory the injectors all share a common 12v feed, and are individually negatively switched from the ecu. The common feed should be the same colour across all of the injectors.

It should work as it is, unless you have the polarity the wrong way.
 
Can't give advice on a method I have not tried...

Personally can't see it working fantastically well on a vag ecu and suspect the I injector input is more for wasted spark and fixed injector duty setups...

Have seen controllers based on MAF input used on vag cars but nothing like this... Not something I would do myself... Vag injector duty is a moving target and not the best way to achieve this imo

<tuffty/>
 
<tuffty/> said:
Can't give advice on a method I have not tried...

Personally can't see it working fantastically well on a vag ecu and suspect the I injector input is more for wasted spark and fixed injector duty setups...

Have seen controllers based on MAF input used on vag cars but nothing like this... Not something I would do myself... Vag injector duty is a moving target and not the best way to achieve this imo

<tuffty/>
Click to expand...

Mmmmmmmm, if I'm completely honest I'm not sure I've 100% understood what your saying there, but I think I get the gist of it... Came across this post where someone had installed on a B5 S4 with good results:
http://www.audiworld.com/forums/s4-...-install-experience-results-long-bww-1540502/

What sort of problems would you expect to incur with this system then? . . Or just shaky and inconsistent meth delivery?
 
VAG-Slag said:
... Or just shaky and inconsistent meth delivery?
Click to expand...

..this would be my expectation....

Without the experience of doing it this way I can only base it on my (sometimes limited) knowledge of how ECU's typically work... this is more Bill's area than mine as he has the experience but typically MAF less and standalone ecu setups you tend to use a 'fixed' duty for injectors and use compensation maps to deal with boost onset etc (expected airflow sort of thing) so the injector duty should be fairly predictable... on ME7 running a MAF then injector on time is a calculation based on many factors as the map is trying to achieve a target AFR... this can be influenced by knock, EGT's and adaptions etc which means that injector duty is determined on the fly... this makes it less predictable...

If your controller supports its you would be arguably better off using MAF input... personally I would just use a boost switch

<tuffty/>
 
<tuffty/> said:
..this would be my expectation....

Without the experience of doing it this way I can only base it on my (sometimes limited) knowledge of how ECU's typically work... this is more Bill's area than mine as he has the experience but typically MAF less and standalone ecu setups you tend to use a 'fixed' duty for injectors and use compensation maps to deal with boost onset etc (expected airflow sort of thing) so the injector duty should be fairly predictable... on ME7 running a MAF then injector on time is a calculation based on many factors as the map is trying to achieve a target AFR... this can be influenced by knock, EGT's and adaptions etc which means that injector duty is determined on the fly... this makes it less predictable...

If your controller supports its you would be arguably better off using MAF input... personally I would just use a boost switch

<tuffty/>
Click to expand...

Ok, I think that helps me understand a bit better... The kit does also have an adjustable boost switch to activate the meth, this is just to determine the amount of meth being injected. If that's what you're saying?

Also, back to a previous question of mine, do you think a constant 12v would simulate 100% duty cycle just for testing purposes?
 
I would seriously consider using a boost switch if your wiring skills are questionable... The injectors are fed a common 12v and switched to earth individually by the ecu... looking at the wiring diagram this is referred to as the pulsed wire I believe...

To be honest I not massively comfortable advising on something I have not done myself especially as I am not convinced of this method of connecting a wmi controller up...

Its not something I would use myself

<tuffty/>
 
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