rusefi.com

This is Weird.

Proteus, 0.7 board with F4 processor. 1996 Alfa Romeo GTV V6 Turbo.
Replacing AEM 308 Sequential Injection, ignition - which did not exhibit any of the following weirdness.

Tachometer Lowside 12, Default Mode, Constant time, 0.5 pulse duration, 3 pulse per rev.
Speedometer Digital 3, 16 tooth count.
Speedometer signal is branched to Proteus from sensor/dash.

When stationary, dash tachometer mimics Tunerstudio.
At low speed (up to around 45km/h) dash speedometer and tachometer work normally.
Over this speed the dash speedometer stops responding to sensor input and follows apparent tachometer motion. Dash tachometer goes to around 3000 and holds.
The above stays in effect even when speeds drop below the threshold. Once stationary both dash speedometer and tachometer revert to normal working until the speed threshold is reached.
Even weirder - when the dash speedometer is misbehaving, activating the turn signal makes the speedometer move up and down in sequence with the signal flashing.

I have tried moving the Tachometer to a highside with no change, no change reversing the output mode or changing to duty cycle.
There is also no change to the weirdness when disabling the speedometer input.


The wiring is unchanged (I'm using the AEM 73 Pin connector) and this did not happen with the AEM.

I have temporarily disconnected the speedometer input to the Proteus

Any thoughts on this?

What is voltage levels for tacho signal? I had to add quite low-ohm pull-up to OD output (to sensors +5V output) to make Subaru tacho work.

Dron_Gus wrote: ↑

Sat May 20, 2023 7:47 pm

What is voltage levels for tacho signal? I had to add quite low-ohm pull-up to OD output (to sensors +5V output) to make Subaru tacho work.

Thanks for that.
I don't have a problem making the tachometer work. Sitting stationary or driving slowly the tach works full range just fine. Moreover it works with both highside and lowside ecu outputs.

With the speed sensor from the gearbox disconnected from the ECU, the dash speedo and tach work fine but I loose the ability to use boost by gear and fine tuning of Decel fuel cut as well as displaying speed on shadowdash when i get around to that.