Fuel Pump control.

[AndreyB]

What kind of logic do we need for fuel pump control? Just always pull down relay output wire when our ECU is hot?

I have created a ticket for the implementation if any code would be needed. No idea if any code would be needed at all - https://sourceforge.net/p/rusefi/tickets/3/

[Sergey89]

After the ECU is powered up you need to turn on the fuel pump for defined time. It is neccesary to make the initial pressure in the fuel rail. You should always turn on the fuel pump when the engine is cranking or running.

[AndreyB]

After the ECU is powered up you need to turn on the fuel pump for defined time.

Is not it just constantly on if the ECU is on?

[Sergey89]

This is not necessary.

[AndreyB]

I have updated the ticket with your proposed algorithm, I guess it would do the job.

[erich]

It's important to turn off the fuel pump ater a couple of seconds of no crank angle changes.
You do not want the fuel pump running for more than a few seconds if the engine stalls for safety.
Think fuel line ruptures.

[AndreyB]

Think fuel line ruptures.

You have convinced me - we do need some code there

[Sergey89]

Pseudocode

Code: Select all

void FuelPumpControl(void)
{
    if (Engine.IsRunning || Engine.IsCranking)
    {
        FuelPump = 1;
    }
    else
    {
        if (Switches.Ignition && FuelPumpPrime) 
        {
            if (!FuelPumpPrime)
            {
                FuelPump = 0;
            }
        }
        else
        {
            FuelPump = 0;
        }
    }
}

FuelPumpPrime is delay.

[erich]

I'd do it with more of a watchdog approach.
Turning on the ECU and getting crank signals reset the watchdog. If the watchdog expires, turn off the fuel pump.

[AndreyB]

Turning on the ECU and getting crank signals reset the watchdog. If the watchdog expires, turn off the fuel pump.

Actually this might be the most elegant way to do this. So on startup you turn it on and you setup a timer which would turn it off. On each shaft position event, you re-start the timer with a new timer further in the future...

Like this approach! Now question who is ready to actually code it

I should add info on timers into the "working with time" section of Source code Q&A

[AndreyB]

Turning on the ECU and getting crank signals reset the watchdog. If the watchdog expires, turn off the fuel pump.

Roman 'frig' has implemented this under https://sourceforge.net/p/rusefi/tickets/3/