MoTeC Global Forum

Hi

I have been trying to control the rail pressure through the pressure release valve. I have connected one pin ofthe PRV terminals to LOW SIDE IGNITION 4 (as injector pins are already allocated for C and D connector we have) and other to 12 V battery supply. It did not work. (The valve is actuating and stuck open continuiously)

Please suggest me the possible mistakes.
Also, I am assuming that the PID control of PRV will be the same as the inlet meter valve (IMV), so I am tuning the same maps.

Thank You

Hi,

I deleted the matching post under M1 Tune.

If you can provide some more details, such as the engine type and the brand/model of HP pump being used this would assist in providing answers to your questions.

Some of the HP Pumps require the use of a bridge output to control their operation, yours may be one of them.

Do you have a measurement of the resistance across the pins of the pump?

Hello
Thanks for the prompt reply..

Actually, the pump does not have an inlet meter valve (which can be controlled by bridge output and we have done that for other engines with Motec).
The current engine (Mahindra Supro) has a cam-driven reciprocating pump (mechanical pump, no electrical points). The pressure is controlled at the rail only by draining the excess through the PRV.

I have attached a schematic of the rail similar to that on the engine.

Hi,

Did you do any captures of how the valve was driven using the OEM ECU?

Hello

In the OEM configuration, there was no common rail rather a fuel distribution box was installed. The system was developed perhaps for cost-cutting which allowed pressure fluctuations compromising with performance.
We have replaced the fuel distribution box with a common rail to get precise control for R&D purpose.

So , we don't have any captures. However, we have resistance across the valve
The resistance is 4 ohms.
attached images of the PRV

Thank you

Hello Ankur,

its possible to do so
please find attached a start file for a 4 cylinder diesel with a Pressure Release Valve.
Just take out the parameter you need.

The Pressure Release Valve is connected to the Bridge Output 1
M142-Pinnout
C18-OUT_HB1 Bridged Output 1.Negative
C01-OUT_HB1 Bridged Output 1.Positive

Most of the PRV need a frequency of 1000Hz
Measure/Adjust also the Resistance from your PRV


You need a Workaround for the Diesel Firmware to get a smooth engine speed signal.
You need one free output, that you can assigne as dummy to the ignition outputs
Assign the number of ignition outputs according to your cylinder number


The start file is in the next answer, 3attachements max

Have fun
Oliver

Here the start file
Check your Hardware/wiring .... .

Oliver

Excuse me if I'm wrong, however, since this post is fairly new I felt my question is better fit here than in a new thread.

My question is regarding an engine that has a 2-liters 4-cyl engine with Bosch CP3s3 Pump, which has both a quantity control valve and the DRV2 pressure release valve.

the M142 Package says in (Fuel Pressure Primary Direct Bank 1):
"Pressure control is achieved by means of a PWM controlled proportional valve which may divert the high-pressure output of the pump back to the feed (low pressure) side, OR directly control the volume of fuel allowed to enter the high-pressure pump element."

is there a possibility of using both valves instead of choosing one method ? I feel like I'm missing something.

I thought of using (Fuel Pressure Primary Direct Relief) but it's only for high voltage valves similar to the one used by the Denso HP5S pump. The bosch valve is only 12V. I can also choose (low side injector/ignition)but this would require an external driver since the current requirement is higher than the Output capability.

Any guidance is appreciated.
P.S: I have access to the development package.

Hi Hashem,

I have used quite a few CP3 pumps in various applications, and have only ever seen them with a single fuel metering solenoid - not with an inlet metering valve

The pumps usually have around a 1.3ohm resistance on the control solenoid, so a bridge output is used for the resource, as this allows finer control.

They are low side controlled with and inverting polarity.

Hello Nathan,
Thank you for the reply, ok things are clearer now and I think I can ask a better question. I've been Gasoline my entire life and I thought I knew everything, Diesel is humbling me.

What I meant was controlling the quantity control valve (located on the pump and Measures like you said 1.3ohms) and the pressure control valve (Located on the Common Rail and measures 5ohms) simultaneously.

The quantity control valve (Located on the pump) as I understand should be assigned to a Full Bridge under (Fuel Pressure Primary Direct Bank 1).

What about the Pressure Control Valve(Located on the Common Rail) ?

Have a nice day.