GP PWM - Econo/Boost gauge setup help.

Hi guys,

I have an e30 sr20 build with a G4x S15 PnP on the go that i am just doing some final little tuning features on it.

Below is the econo gauge (l/100km) for a standard e30 - I believe it used injector duty cycle as an input in its standard form.

What I'm looking to do is set it up as a boost gauge.

I managed to activate it on AUX 2 with Test (PWM) or ON and it conducted a full sweep.

With some help from the linkecu forum i managed to setup a single cell where I could enter different Duty Cycle % (For Eg 10% below) to establish what duty cycle would result in say a value of 10,20,30 with the needle on the gauge.

Unfortunately, no matter what i do, i cant get it to stop at the increments. At 50hz i had '1.1' in the cell and the gauge would be off or zero, if i set it to '1.2' it would max out to 30/full on the gauge. So ive got no range to work with at 50hz, at 250hz the gauge will sweep back and forth when '17' is inputted. Any other value in the cell results in much of the same, either off or pinned at max/30.

I've tried different frequencies and dont appear to be getting anywhere.

Ive put the word out to some fellow e30 owners in my area so i can check what the standard ecu outputs in terms of Freq/Duty Cycle but im not getting any love at the moment.

Any advice moving forward on how to determine a devices working freq or duty cycle would be much appreciated.

Cheers, Ryan.

It may need a pull up resistor/power supply to work properly too as if it was fed from an injector output it would have been getting positive power during the off phase of the injectors.

Cheers for your reply Michael, i managed to sort it out this morning. The economy gauge required a wheel speed, rpm input as well as the injector pulse which would then be all calculated by the solid state goodies in the cluster and outputted accordingly on the gauge. I managed to get it to stop at the increments i mentioned once i got the vehicle speed and rpm high enough.