Sparktech COP CDI Factory Tach not working

[J_HEATH]

HELP!

I contacted Sparktech and they told me they weren't sure that they usually use an aftermarket tach with this setup.

I have a 93 AWD Auto DSM and I recently installed a Sparktech CDI COP (pro) and now my factory tach doesn't work. I've chased wires and checked. I get a tach signal on DSMlink V3 and it works fine on there, just the Tach on the gauge cluster doesn't work.

I'm wondering if anyone else has had this problem or knows where/what I need to wire up to get my factory tach to work again.

I can't retune my car until I get this issue resolved.

Thank you for any feedback and help

J. Heath

 

[rts91tsi]

Which exact CDI system did you buy?

According to the FSM, the same white wire from pin 4 of the PTU connects to pin 109 of the ECU, but it feeds the tachometer before it gets to the ECU.

Did you run that wire straight to the ECU?

 

[J_HEATH]

Which exact CDI system did you buy?

According to the FSM, the same white wire from pin 4 of the PTU connects to pin 109 of the ECU, but it feeds the tachometer before it gets to the ECU.

Did you run that wire straight to the ECU?

I have the M&W unit.

Spark Tech DSM System with Pro12CDI unit. [COPDSM-12] - $1,103.12 : Spark Tech, The Online Store

I did not run any wire for tach to the ECU. I was told (by sparktech) that I only had to run 5 wires.

2 directly to the ECU (coils 1&4, 2&3), a constant 12v, ground, and a switchable 12v.

It has a Tach wire (green) but was told I didn't need to run it as its for using an aftermarket tach. This wire I'm sure is the wire that needs to go somewhere to link up with the stock tachometer. Where is what I'm trying to figure out.

I'm almost positive I tried using the PTU white wire but got nothing, also the car wouldn't start with it connected there.

 

[rts91tsi]

There is a inverted logic gate inside the PTU, at least that is what the FSM shows, which is probably why you didn't have any luck using the white wire.

I honestly don't know what else to suggest, hopefully someone has an answer for you. Sorry I could not be of more help.

 

[J_HEATH]

There is a inverted logic gate inside the PTU, at least that is what the FSM shows, which is probably why you didn't have any luck using the white wire.

I honestly don't know what else to suggest, hopefully someone has an answer for you. Sorry I could not be of more help.

I appreciate the effort.

I called AMS and a guy there (sorry don't remember his name) told me that they have installed them on 1G's before and the tach works. I just need to get my multimeter out and start tracing wires.

 

[2gdanny]

I know it's a old thread, but I'm wondering if the op got this figured out, I'm in the same boat, I have not tested any wires from the ptu, I did find out that the ptu can't stay connected the car won't start.

 

[J_HEATH]

Let me resolve this thread,

I spoke with sparktech and they told me "most people" with this setup run an external tach. I though that would have been some good information before I purchased it.

Well I pulled the gauge cluster, traced wires and found out which wire was the tach signal wire and ran the GREEN signal wire into the cab through the firewall and soldered it directly to that wire. Now the factory tach works.

 

[____Kurt____]

I just picked up the pro Cdi unit and I will be installing it today, I'm glad I read this thread first because I will not be running an aftermarket tach and I would like to see my rpms . So I will follow the instructions and if something don't work I know what it is. Good thread.

 

[J_HEATH]

I just picked up the pro Cdi unit and I will be installing it today, I'm glad I read this thread first because I will not be running an aftermarket tach and I would like to see my rpms . So I will follow the instructions and if something don't work I know what it is. Good thread.

Feel free to reply to this post or PM me if you have any issues. I'm sure I could help you trouble shoot and solve any you come across. I think I had every issues you can have with this setup

 

[2gdanny]

Feel free to reply to this post or PM me if you have any issues. I'm sure I could help you trouble shoot and solve any you come across. I think I had every issues you can have with this setup

after your help i still wasn't able to get my tack working, no big deal i have the car at my tuner for a week

and let me tell you he ran in to so many problems with this that i don't even know how he fixed it.
Monday he said he got the car started but timing was every where, and that fire sequence was all out of control

he asked me to bring the stock ignition to test stuff out, today he texted me saying it should be done this week,

 

[J_HEATH]

Okay, if the firing order was off then like me the 2 wires going to the ECU are opposite of what the directions said. I had the same issue and swapping the wires fixed it.

 

[2gdanny]

that was one of the things i had tolled him about and i think that fixed it, till there was something else with it, its still at the tuners, and my guy works at Ferrari so he doesn't have much time to tune and trouble shoot it, he tunes racing ferraris

 

[____Kurt____]

My solution was I had to unplug the Power transistor and solder the green wire (tach signal) from the cdi to the white wire (number 4) on the power transistor plug and now my tach works.