After reading the 034 tuning manual, seems like my 1996 VW tachometer is consider as old ones since it's not functionnal...

what's the solution ? Signal converter ? Which one is recommanded by the guru in here ?

thanx

David

Depends on how the stock tach was driven. Chances are it was wired up to your old stock coil. In which case you need one of these:

http://www.034motorsport.com/product_info.php?products_id=760

gotcha ! thanx

This raises a question I have been trying to get a straight answer to.
I have heard and read that the Mk3 Jetta/Golf tachs are driven from a digital signal from the ECU, and that the only reliable way to get the factory tach to work is to keep the OEM ECU in place and powered, and given a rpm signal from the crank trigger.

Can anybody support or refute this? If this is true, would splitting off the signal from the VR sensor to both the factory ECU and the 034 ECU cause problems?

I'm planning on ordering the remainder of the stuff I need in the next week or so (flying lead harness, 034 16v coil mount etc), and I'm trying to determine if I need the tach converter or not. I'll be running Ic as well.

yes it works.. BUT the main idea to go SEM is to kick the ecu stock out of the car !!

The way that OEMs are designing stuff these days, its becoming harder and harder to separate vehicle subsystems since the ECU is interfacing more and more items and the lines between are them much more blurry and proprietary.

Well, I dunno, it ran the car just fine for the last 11 years or so. It just won't do what I need it to anymore, that is control a boosted ABA 16v. I'd be more than happy to just have it sit where it is if it's only real task is to operate the cluster. I'm not putting the 034 ECU where the OEM unit is anyway. As long as somebody has ACTUALLY tried this and it works, I'll go ahead and do it.

bump from the dead !!!

Sorry, with the 034M tahc converter... still not working... rewired completly the engine harness... still not working... Signal for the ecu output, signal from the wire behind the cluster... Shorting wire to ground the needle of the RPM moves, but when everything is connectec as it shoudl be... no rpm...

Bad cluster ? Absolutely need stock ECU with Ic ?

help required please

the 034 ecu signal is an analog or digital signal ?

Its niether or both depending on how you define analog and digital.

Its a signal that goes (digitally) from 0v and 12v for each ignition phase defines.

Most tachs deal nicely with this, some do not.

thanks... we'll try to continue to track the problem...

tried another cluster, no rpm
tried another Ic ecu with my log downloaded into, no rpm
tried an autometer rpm straight on the signal of ecu, not workin either...

still tracking down...

Do you have the "enable tach" checked for the ignition phases?

will recheck but my friend said yes to me on that one...

is this MSD tach adapter inside the box?

­@ Architect: yes it is..

tried all MSD tach adapter, none is workin in my car...

Well there several potential issues:

1) The Tach output is not pulsing as the engine turns/runs.
This can be verified with an o-scope connected to this signal wire, it should spend most of its time at 12v and should go near ground for 1ms for each active tach phase degree setpoint. A voltmeter could yield a "crude" determination that it "may" work since the voltage will begin near 12v and get lower and lower as the RPMs rise in proportion to the increasing duty cycle of the output signal.

2) The 0 to 12v signal is not compatible with the cars tach input circuitry (in most cases the MSD amplifier solves this issue).

3) You have some sore of wiring issue between the tach output pin and the vehicle tach input.


I cant think of any other thing it could be.

thanks for the hints

Do I need an adapter for a 1987 Cabrio tach?
In my other MKI (1978) I run a digifiz out of a MK2 (1988) and the tach works with the 034.