I have a classic, I believe to be version 3/4 wiring (3 plug ecu, version 3/4 engine, pre facelift dash), running an alcatek and the speed signal the ecu is receiving is very scattered, and does not register anything on the ecu under around 30mph, and when it does get a signal it is not stable. This is causing headaches when trying to setup the launch control and anti lag as they use this as an input
I am trying to trace the wires through the car but I'm struggling as the wiring diagrams that I have do not match what is on the car?!
The speed signal is mechanical from the gearbox to the instrument cluster. From within the cluster it is then changed to an electronic pulse signal and goes to the ecu. I cannot find a connection between the ecu and the cluster from the location I know the signal comes from the cluster.
I have tried 3 sets of clocks and the issue is the same with each set. I am seeing the correct speed on the instrument cluster with each set of clusters. But still a scattered speed reading at the ecu
does anyone have any ideas of what I can try to resolve this?
Also, if anyone has a wiring diagram or pinouts for the ECU with 3 yellow connectors it would help enormously

cheers
tom

 

ECU pinout:

http://www.enduringsolutions.com/ECU978pinout.pdf

 

Did you have a look on the Ken Gilbert site for wiring diagrams?

 

I didn't look there, thanks, I will have a nose!

 

It's a great site, nothing specifically for the V3/4 except the 1998 Australian version. I used that diagram for my car and was fine though. My car is an odd ball, seems to be some sort of parallel import almost. The applied model code appears all over Australian stuff and not so much in the UK.

 

Tom my car the same but no speed input at all so be good to find this out.

 

Turned out to be a speed delimiter which was messing with the signal

 

Nice one mate, at least you're sorted!

 

The anti lag and launch functions work now, but the signal still isn't as good as it needs to be for other function to opperate perfectly, the ecu isn't seeing anything atall under 15mph and is still a little scatty.
We're going to try replacing the reed switch on the back of the Speedo with something better as I'm hoping to run the terratrip from this signal, so it needs to be accurate.
Doing this and inputting ratios into the ecu tables has also enabled the ecu to calculate which gear it's in, so we can now tweek the map according to the gear it's in.
Little by little the car is improving.

Next up is wiring in the DCCD as there is no wiring atall for it in the car. No speed sensors on the wheels, g sensors or any of that good stuff.
I do rather like it set in open though, it drives like a very well planted rear wheel drive car which suits my style 😊 and if you're super aggressive with it you can pretty much drift it. I'll post a video up of the shakedown run I did a few months ago on my build thread, when I get chance