I am running an E8ecu but all my aux outouts are used up. I need an rpm signal to feed my avcr boost controller. I have seen mentioned somewhere about the trailing output to the coil is this true?

 

First, you'd need to know what kind of signal your boost controller wants to "see".

5V square wave?
12V square wave?
Primary ignition to coil?

then look at what kind of ignition you are running,
smart coils?
dumb coils?
waste spark?
full sequential?

now figure out how to match up what you got to what you need

I'm sure you aren't the only one with your particular setup, so post some details and maybe someone can give you a step by step way to get it done.

 

How are you driving the tach in the cluster? Use the same signal.

 

The tach in the cluster is still driven from the stock system. I have been trying to figure where it gets its signal from, does anyone else know? If its not from the stock ecu(replaced by haltech) I could use this signal for my BC.

 

Open your tune with the haltech tuning software and see which output is configured to drive the tach. Then look at the wiring diagram for your haltech and see which wire that is

 

Actualy the Haltech is not setup to drive any tach at all. My stock tach does not work even before the stock ecu was disconnected, and is a different matter altogether related to the FD's odometer problem.

Does anyone know where the stock FD tach gets the signal?

 

In the original ECU harness, connector 2(12 pin) position B it's a yellow/blue (Y/L) wire.

At least I think that's it, I'm in the process of getting this car running, and I hope to crank it over later today and see if that actually works!

 

I think you are correct because thats the pin to tap into to obtain RPM signal according to the avcr manual. Well, since my stock ecu was disconnected I lost that signal, which would mean that is an output from the ecu, rather than an input. That is probably the signal that feeds the stock tach also.

 

Yes the stock ECU sends a signal via that wire to the instrument cluster.

The haltech can be configured to do the same. But if you have used up all your outputs then you are gong to have to switch one of those outputs to drive the tach of try picking up a signal elsewhere.

that goes back to what I said in my original reply

 

What are you using all the outputs for? Hard to believe you're running that many accessories.

 

Yea!! I really have the e8 doing its work.

 

No, I meant give me a list of everything you're running. Perhaps we can free up an output and get your tach and boost controller working. Post your map or email it to chris@lms-efi.com

 

water inj
temp switch for fans
temp switch for hi temp warning led
bac
shift light

Wy harness is missing 3 wires.
Ignition 2
Aux out 1
Aux out 2

Could you say what the deal is with Aux out 2?
I see it on the E8 output screen but dont see it on the wiring diagram as an existing pin out.

 

Move whatever you have assigned to PWM1 to one of the channels with the missing wire. I can provide terminals or pigtails. Set PWM1 to tach output. 4 pulses, 50% duty, 12V pull-up. Connect that to the stock ECU terminal you guys were discussing in this thread and gang your boost controller on to that output. Problem solved.

Aux 2 is there, it's just not populated. Add the terminal and you can use it. It's pin 30 on the 34 pin connector.

 

Thanks to you guys for the advise.
Ludwig, I will be sending you pm.

 

Update: I was able to get everything working including the stock tach. I used PWM 1 as Chris suggested for the rpm signal to the BC. I went a step further and attempted to tie this wire directly to the stock tach to see if it would work, and It did. I totally insulated 2 of the three terminals located at the back of the stock tach from its original connections. The third connection (ground ) was left as is. One of the two insulated terminals was connected switched ignition, and the other was connected to PWM 1. Surprisingly, it worked and this means the stock tach can be run by a standalone ecu independant of the stock circuitry in the cluster. This is a useful fix for FD owners who have a dead tach caused buy a faulty circuit in the cluster.

 

Great, it's always good to see someone get it done!