Peugeot 407 crank non start Cam/Fuel Pressure

[chris.mogs]

Hi
Vehicle: Peugeot 407 2.0 HDI 136BHP RHR.
P1164 Pressure to high or too low when cranking.
P1197 Harness, injector, ECU power stage.
Recon pump, Injectors, new fuel regulator and fuel pressure sensor.
Original fault was low pressure on crank(47bar).
Reference fuel pressure: 350bar
Measured fuel pressure: 1090bar (too high for starting)

The first thing I need to mention is that she will start using easy start. My understanding is that if the ECU does not see the correct cranking pressure it will not release the voltage to the injectors for the pulse to occur and deliver fuel into the cylinders.
I have checked the harness for continuity and resistance and have found no fault. Initially I suspected the ECU as there was an absence of battery voltage at either side of injection circuit. I have now dismissed that idea for my reasoning above.

In regard to the fuel pressure test the capture above looks nothing like the wave in the guided test. I appreciate this is during cranking, but I would have thought there would have been some kind of a partial wave showing a pressure build especially as I now have to much pressure. Anyone any ideas as to why the capture looks like this? Also how do you work out voltage to fuel pressure?

During a recent scan there was no confirmation of cam syn. I removed the sensor and tested the harness. This is a pull-down design with a 5v reference which shows 0v when plugged in. I plugged the sensor in and used a spanner to drop the voltage on and off so no fault there. As you can see from the capture the cam pulses are there now, but I am concerned about the degradation of the signal at the top of the wave form. Could this be indicating a faulty sensor or some other issue and could there be a correlation between
the two?
I’m new to testing with a scope having purchased a 2006B but it is very interesting to see why a scope is so important on modern vehicles.

I look forward to any advice and guidance just point me in the right direction and I will report my findings and hopefully I will be able to see this car running again.

Many thanks,

Chris

[landroverman1958]

Hi Chris,1st things 1st, check the voltage at the rail pressure sensor,koeo hould be around .5volt,then unplug sensor to see if the voltage goes up to reference voltage,possibly 5volts.
Check the primary supply to the high pressure pump for good flow no aeration,if supply is good,do a cranking test,with the injectors disconnected electrically at the plugs on the injectors.
Then disconnect the metering valve,if there is a pressure regulator on the rail disconnect,the rail pressure should build up within half a second to full rail pressure,see how these tests lead your diection.

[autobrejo]

hi landroverman1958, i've got on my garage a 407sw 2.0 rhr and the problem are the ecu, on beginning i change the fuel pump, the pressure regulator, the rail sensor, the fuel filter but the pressure on rail doesn't increase (just max 90bar on start), after many days and a lot of study, i change the ecu, in this case i change a complete used kit, ECU, DASHBOARD, KEYS, BSI and BSC(rear).
i hope this help you,
best regards