2.5 vs 1.8t coilpacks

[bikerjim]

Having been reading up on conversions for the 1.8t engine it seems that the best way vw ground is to have2 separate ground points, otherwise you can end up with some kind of back loop going on?!

[UrS4boy]

Having been reading up on conversions for the 1.8t engine it seems that the best way vw ground is to have2 separate ground points, otherwise you can end up with some kind of back loop going on?!

In the original wiring system, one of the grounds was for the POSs and the other was for the (separate) coils. The POS ground was Pin 2/4 of the POS connectors which went back into the harness (and eventually to the intake manifold). The other ground was for the coils and was attached to the rear of the cam cover. I presumed that the coil packs needed the same two grounds when I developed the first (documented) trial of the 1.8t coil packs on an AAN. (So I agree with you Jim)

[dspl1236]

i had my coils wired in the same fashion per your diagram but no go on any coilpack for months

The guy i bought my standalone came over saturday and had me swap pins 2 and 3....we get spark....but only on 1.8t coils. I am very confused

only way to get spark
pin1 - 12v
pin2 - ecu
pin3 - 12v
pin4 - ground

also worked...but again only on 1.8t coil
pin1 - 12v
pin2 - ecu
pin3 -
pin4 - ground

[UrS4boy]

Okay. I have *no* idea, nor do I want to have an idea, how your stand alone ECU works (or in this case, doesn't work). All I can tell you is the "proper" wiring for the 4 pin coil packs for the AAN (or ABY or ADU) Motronic ECUs is:

Pin 1 = 12v Power
Pin 2 = Harness Ground
Pin 3 = the specific ECU harness wire that controls *THAT* cylinder
Pin 4 = Engine (cam cover) ground.

As I have said before to people who make the jump from 3B to stand-alone with coil-on-plug coil packs, you should do an intermediate step using the Motronic ECU so you know that your coil pack wiring is working first, before you move on to the stand-alone.

[prj]

Pin 3 is definitely control ground.
You ground it to start charging the coil, and you release it to make it spark.

Use 2ms dwell.

[dspl1236]

thanks guys. i am going to pass on the vag coils and look into other coil options at this point

[UrS4boy]

thanks guys. i am going to pass on the vag coils and look into other coil options at this point

If you haven't already, contact Marc S. at EFI Express. He will sort your ignition wiring and coil issues out, and, if necessary supply you with an LS2 coil kit. You might still have basic ignition wiring problems regardless. Contact Marc.

[dspl1236]

If you haven't already, contact Marc S. at EFI Express. He will sort your ignition wiring and coil issues out, and, if necessary supply you with an LS2 coil kit. You might still have basic ignition wiring problems regardless. Contact Marc.

My DTAFast P8 Pro even says that it does not like the VAG coils. the only mention it has is about the early bolt down coils might need a pull up resistor ....but again i have asked a few folks about how to wire in the pull up.....i get different answers.

ya marc knows his stuff...but dont want to bother him since i have never purchased anything from him. Maybe ill have him remote in someday at the dyno.

summitracing is only 15min away

[dspl1236]

how would i wire in said "pull up"?

[UrS4boy]

How to wire "said" pull up

Based on the info in the DTA diagram, specifically the note that the coil designations in the stand alone are NOT firing order.

Based on the Audi 5 cylinder firing order of 1-2-4-5-3 and the ECU Coils 1 through 5,I believe the wiring would go as follows:

Cylinder 1
Pin 1 = 12v Power
Pin 2 = Harness Ground
Pin 3 = "Coil 1" in the ECU stand alone harness
Pin 4 = Engine (cam cover) ground.

Cylinder 2
Pin 1 = 12v Power
Pin 2 = Harness Ground
Pin 3 = "Coil 2" in the ECU stand alone harness
Pin 4 = Engine (cam cover) ground.

Cylinder 3
Pin 1 = 12v Power
Pin 2 = Harness Ground
Pin 3 = "Coil 5" in the ECU stand alone harness
Pin 4 = Engine (cam cover) ground.

Cylinder 4
Pin 1 = 12v Power
Pin 2 = Harness Ground
Pin 3 = "Coil 3" in the ECU stand alone harness
Pin 4 = Engine (cam cover) ground.

Cylinder 5
Pin 1 = 12v Power
Pin 2 = Harness Ground
Pin 3 = "Coil 4" in the ECU stand alone harness
Pin 4 = Engine (cam cover) ground.

[dspl1236]

ok here is what i have been instructed.



.
.
.
.
but no spark. There is a test mode that fires coils and injectors together in 1k steps to programed limiter. this is what i have been using.

i have the 2.2k resistors. do i put these inline on my ecu to coil wires? do i bridge the resistor across pins?

[UrS4boy]

ok here is what i have been instructed.

Your instructions are wrong. The Audi 20VT firing order is 1-2-4-5-3
NOT 1-5-2-3-4. That is your first problem.

My suggested coil control connections are correct for the Audi 20VT.

[dspl1236]

ok going to try this.

[prj]

The instructions sound horrible.

Running it like that is not good for the life of the coils, especially at higher revs, and also there is no sequential injection

[UrS4boy]

ok going to try this.

I have you grasped the firing order error problem yet? (You didn't comment on it)

I have no idea what the coil diagram is from but it is not a VAG coilpack. Good luck.

"Try"ing is dangerous (expensive) if you don't understand what you are doing.
You would be WAAAAY better off to buy an hour or Marc S.'s expert time to sort this problem out once and for all. - Even if you don't buy anything from him (e.g. an LS2 coil kit). Pay for his time and get it sorted.