CR general - Rail pressure too high

Hi,

What ideas come to mind for repurposing an old...?
CR system (example with a CP3 pump and a flow control valve).
Why is the rail pressure so high (>800 bar), even when the engine is idling?

'The first thing that comes to mind is the control valve itself, but it seems to be working fine.'
'because if you directly connect the grounding terminal to the power supply,'
Then the engine shuts off nicely.
Okay, so it can start and stop. Since the engine starts and also...
and can also be switched off electrically.

To what extent does the return flow and its quantity influence...?
What is the prevailing rail pressure? Please provide the text you would like me to translate from German to English.
What would happen if you blocked the return channel?

I mean, the return items are plastic tubes, and they can...
certainly not withstand high pressure, and yet...
possibly Constipation and the resulting increased pressure in the RL (presumably referring to a specific medical device or area).
'First, quit the service and then explode/leak?!'

Actually, I would expect that if there is a high return rate...
'some injectors may have a defect, and accordingly...'
the rail pressure would decrease (e.g., due to a clogged injector).
and in the extreme case, the engine might not even be able to start.

It's also conceivable that the Murks rail pressure sensor is faulty.
but that has been proven not .

Another idea would be the transmission itself, but I 'don't want' to .

I'm somehow missing the bright light bulb right now.

Hi, what pressure is displayed when the engine is off and the system is completely depressurized? Is the pressure value perhaps just a placeholder value?
Best regards.

The ignition pressure value seems to be within the acceptable range so far.
Even when the exhaust is turned off, the system correctly identifies the atmospheric conditions.

And what if you unplug the connector from the mass airflow sensor? And does anything come out of the pump's return line?

It doesn't even start if the plug isn't connected.

Hi,
What does the error memory say?
And - are 800 bar too high? http://www.amz.de/fileadmin/epaper/amz/amz_2009_Diesel_spezial/amz_2009_Diesel_spezial.pdf
Page 4.
hg
Herbert.

The error code indicates 'P0191: Fuel rail pressure deviation.'
And yes, the target pressure is a maximum of 320 bar for the small 1.9-liter engine in low load conditions.

Isn't that the minimum pressure?
hg
Herbert.

No, 240-320 bar is the target idle pressure.
And that's how they work, I checked with a colleague.
'It's running smoothly and peacefully.'

Do you still have a pressure regulating valve on the fuel rail, or not? Is fuel coming out from the return line? Does the engine shut off if you unplug the connector while the engine is running, or does the pressure just drop?

The Rail does not have a regulating valve; it only has a mechanical pressure relief valve.
which opens at approximately 1500 bar.
If I unplug the connector from the pump controller, it turns off.

Hi,
Perhaps a bit of structure would help (you know, the crystal ball).
- What vehicle, year of manufacture, and engine type?
- What are the complaints in the system (besides errors in memory)?
- Can the error be cleared? If so, when will it reappear?
- Perhaps a log with rail pressure readings starting from engine start, at idle, during operation, etc.
hg
Herbert.

2006 Renault F9Q 760 1.9 74kW engine.
'Error occurs during ignition, engine shuts off.'
is immediately (and correctly) included again after the start.
Complaints: The engine makes a loud, animal-like noise and stalls when the RPMs increase.
The pressure exceeds 1500 bar, and the safety valve opens.
Log, none available...

Hi,
The question is why the pressure isn't being regulated via the quantity control valve.
Sure, here's the translation:

"Off the top of my head, I can think of:"
- Defective valve (although the fact that it shuts off when the plug is pulled suggests otherwise); it might just be stuck.
- No return path (exotic, and also argues against the possibility of switching it off).
- Valve control.
Since it likely operates via PWM, does your diagnostic tool allow you to observe the duty cycle of the control signal? Alternatively, you can measure it directly using an oscilloscope or a DMM (the latter should be tested on a working PWM circuit first).
Perhaps replace the PWM signal with an external source to see if the pressure decreases.
Is there something like an actuator diagnostics for mass flow control valves?
hg
Herbert.

Pressure regulating valve is stuck.

Yep, that's it... replaced the new pressure relief valve - 280 bar at idle.
Even if we went as far as to say that there were no errors.
and also that it can be stopped by reducing or increasing the amount.
Could it really be the valve? It probably just stopped working.
reacted appropriately.