Mini Cooper S (Petrol / Benzine) 2007

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Mini Cooper S (Petrol / Benzine) 2007

Post by STC »

I have this beast with issues.

My first thoughts are that it has insufficient Fuel Pressure in the Common Rail. Live Data confirms this for me but I want to be certain that the FRP is not at fault. Do not want to shoot the messenger.

What tool are you guys using to measure High Pressure in the Rail to confirm or deny FRP accuracy in GDI Petrols ?

Any advice, as always, gratefully received.

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Re: Mini Cooper S (Petrol / Benzine) 2007

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Dcunning35
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Re: Mini Cooper S (Petrol / Benzine) 2007

Post by Dcunning35 »

The video is ok but I think stc,s point is to prove out the rail pressure with a gauge rather than rely on the serial analysis. Ok we could check the frp sensor voltage but this doesn't help with a decay check on the injectors.
The ford gdi injectors can dribble and are difficult to find without removing them .
Danny

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Re: Mini Cooper S (Petrol / Benzine) 2007

Post by Dcunning35 »

This is where a piezo clamp on the rail supply line would be worth a try .

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Re: Mini Cooper S (Petrol / Benzine) 2007

Post by STC »

Danny

That video is a waste of time, more about how NOT to diagnose a customers car or come the conclusion that the pump is faulty, that's just parts darts !! Plus it is in Incorrect in several ways, that includes the test procedure and the scan tool.

Good ole Googlenostics :D :D :D

1. It is the In tank LP Pump that has a Desired of 5 bar - So it seems he is manipulating that Scan tool, or the tool is wrong !!! It clearly refers to "Rail Pressure"
2. The desired Rail pressure for "Cooper S | 2005 - 2010 | 161 Hp | N14B16A" Engine is 50 bar at Start & Idle up to 120 bar at Full Load (Typical GDi Figures)
3. He is correctly measuring the Supply Side Pressure but fails to measure volume/flow.
4. If his In tank LP Pump is not failing then from experience he should have a constant 5 bar at the Rail - Coming / Bleeding through the failed HP Pump (have seen that on other GDi's)

To my knowledge this does not have a Low Side Pressure Sensor (could be wrong)
to measure High Pressure in the Rail to confirm or deny FRP accuracy in GDI Petrols ?
That was my question ?

I do want to measure the actual Pressure in the Rail whilst manipulating the Inlet Volume Control Valve with a Gauge or better still a Scope for independent verification and accuracy of the FRP output before I condemn the pump in error.
This is where a piezo clamp on the rail supply line would be worth a try .
Indeed yes, except for the fact that this will start and run. Just that it wont run very well. A Pre & Post fix analysis with the Piezo may prove useful in the future. The Injectors are firing, not checked but I guess the durations will be huge as it begs for fuel ?
The ford gdi injectors can dribble and are difficult to find without removing them .
Another way is to pull the Spark Plugs and sniff for HC's in the hole, useful when the injectors are not so easy to get at.

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Re: Mini Cooper S (Petrol / Benzine) 2007

Post by Technician »

STC wrote:Danny

That video is a waste of time, more about how NOT to diagnose a customers car or come the conclusion that the pump is faulty, that's just parts darts !! Plus it is in Incorrect in several ways, that includes the test procedure and the scan tool.

Good ole Googlenostics :D :D :D

1. It is the In tank LP Pump that has a Desired of 5 bar - So it seems he is manipulating that Scan tool, or the tool is wrong !!! It clearly refers to "Rail Pressure"
2. The desired Rail pressure for "Cooper S | 2005 - 2010 | 161 Hp | N14B16A" Engine is 50 bar at Start & Idle up to 120 bar at Full Load (Typical GDi Figures)
3. He is correctly measuring the Supply Side Pressure but fails to measure volume/flow.
4. If his In tank LP Pump is not failing then from experience he should have a constant 5 bar at the Rail - Coming / Bleeding through the failed HP Pump (have seen that on other GDi's)

To my knowledge this does not have a Low Side Pressure Sensor (could be wrong)
to measure High Pressure in the Rail to confirm or deny FRP accuracy in GDI Petrols ?
That was my question ?

I do want to measure the actual Pressure in the Rail whilst manipulating the Inlet Volume Control Valve with a Gauge or better still a Scope for independent verification and accuracy of the FRP output before I condemn the pump in error.
This is where a piezo clamp on the rail supply line would be worth a try .
Indeed yes, except for the fact that this will start and run. Just that it wont run very well. A Pre & Post fix analysis with the Piezo may prove useful in the future. The Injectors are firing, not checked but I guess the durations will be huge as it begs for fuel ?
The ford gdi injectors can dribble and are difficult to find without removing them .
Another way is to pull the Spark Plugs and sniff for HC's in the hole, useful when the injectors are not so easy to get at.
STC wrote:Danny

That video is a waste of time, more about how NOT to diagnose a customers car or come the conclusion that the pump is faulty, that's just parts darts !! Plus it is in Incorrect in several ways, that includes the test procedure and the scan tool.

Good ole Googlenostics :D :D :D

3. He is correctly measuring the Supply Side Pressure but fails to measure volume/flow.
4. If his In tank LP Pump is not failing then from experience he should have a constant 5 bar at the Rail - Coming / Bleeding through the failed HP Pump (have seen that on other GDi's)

To my knowledge this does not have a Low Side Pressure Sensor (could be wrong)

Interesting, remember the Land Rover. Low side fuel pressure using a gauge was 2.6 bar all day with the pump running but the engine off. When the engine was idling the 2.6 bar pressure dropped to 0.6 bar and running problems were present. The scan tool actually read live data but gave inconsistent readings because the low side fuel pressure was varying considerably all the time, hence live data was unreliable, but the gauge test proved the low side pressure was OK.

I had to buy a tool to remove the high pressure pump without having to remove the engine to change it, when the HPP was changed the low side fuel pressure maintained 2.6 bar running.

The scan tool he uses in the video is AutoLogic, he actually shows the desired low side fuel pressure at 5 bar, and the actual low side fuel pressure starting off at something like 0.64 bar, then increases when revving the engine to around 5 bar, hence the desired and actual are approximately the same.

You can't achieve good fuel volume at cranking speed and reach the conclusion that the fuel pump is performing OK, hence the fuel pump must be capable of delivering the correct rated fuel pressure to provide the correct fuel volume under demand for the engine, I don't think it would work the opposite way round.

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Re: Mini Cooper S (Petrol / Benzine) 2007

Post by STC »

he actually shows the desired low side fuel pressure at 5 bar
No he does not - Look at the picture !!!
For Dinlo.JPG
You, Him and the Autologic are wrong. "Rail Pressure" is underlined for you.

Look in the Orange Highlighted Text at the top " HIGH PRESSURE FUEL SYSTEM" Doh !
Last edited by STC on Sat Mar 18, 2017 8:21 pm, edited 1 time in total.

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Re: Mini Cooper S (Petrol / Benzine) 2007

Post by steevegt »

This is where a piezo clamp on the rail supply line would be worth a try .
Indeed yes, except for the fact that this will start and run. Just that it wont run very well. A Pre & Post fix analysis with the Piezo may prove useful in the future. The Injectors are firing, not checked but I guess the durations will be huge as it begs for fuel ?
Hi STC,

I will have to agree with Dcunning35.
With the piezo clamp, in theory, you could make some validations on the sensor, trying to find it is acting as it should or not.
For instance you could compare rise time (at crank, WOT, 100% forced duty cycle controll), side by side, using the sensor output and the calculated value of the piezo clamp. If the sensor has failed in a way that it is affecting the response time, you will see it in here.

Also, if the sensor has produced some kind of blindness over/below a certain pressure, you also may find it.

Generically, intermittent changes in the signal voltage that are not occurring in reality in the rail pressure, you most likely will find it.

However, if the sensor as failed in the way that the signal has been somehow proportionally compressed, you will not find that this way...

By the way, that system has some kind of backup strategy in case the FRP sensor has implausible value?
If yes, you could just unplug the sensor and validate if the performance symptoms are still present. Not a 100% fail proof test, and has some variables, but if the car runs good with the sensor unplugged, it may point to faulty FRP sensor.

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Re: Mini Cooper S (Petrol / Benzine) 2007

Post by STC »

Hi Steeve

In the end I bought 2 Piezo clamps so I would be able to compare a good and bad side by side but have not used them yet. Do I really want to start learning on a bad car ?

You make some valid points but all I want to do is accurately measure rail pressure and make a diagnosis on hard, measured, verified facts. It has already been off the road for a year so a few more days will not hurt.

Once I have concluded what is wrong and have the actual pressures to hand, I will see if I can get Piezo Waveforms before and after I fix it. A case study from beginning to end with all the fact present

I have no issues spending the money to buy the tools required. For sure I will need them again. I have a Delphi Diesel Sealed Rail Kit capable of measuring ~2000 bar that I could adapt.

Disconnecting the FRP on this is not an easy option, Inlet manifold would have to come off. I could cut the signal wire at the ECU end to promote some back up strategy ? Bear in mind that this car does have a fault and is quite likely already running a back up strategy

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Re: Mini Cooper S (Petrol / Benzine) 2007

Post by Dcunning35 »

Stc ,may I ask where you sourced your piezo clamps from?
Danny

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