G247 Fuel Pressure Sensor Help

[A4 Lad]

IF there were no rich and lean (yes, both) lambda errors indicating that the main pressure pump was low in delivery and leaking fuel into the engine, hence rich and lean codes together which in normal circumstances doesn't add up.

Thats pretty messed up. To be honest, faults like that could easily be mistaken for the ecu losing the plot by the way, the Weitec coilovers on the A4 are still as smooth and doing a good job as the day I got them from you
PS - Do you remember 'roughly' how much the lift pumps are and are they only available through Audi etc ?

[A4 Lad]

ok, a little update, the rain is pishing out of the heavens today so I have not checked any of the mechanical stuff but did find a few interesting readings on the computer. I had previously erased the fault yesterday and had an 80 mile round trip to make today so before I set off, I rechecked for faults... NO FAULTS FOUND ( as expected ) and I checked the MVB 103 and 106 with the engine at idle and this is where I think I might have found some strange readings. I have attached a picture from my phone to show yous. In MVB 103, the Fuel Pressure Regulator measurement shows -71 in the first picture where as when you hover over it, the reading is suposidly to be between 1300 - 3000 mbar at idle ( or something like that )
I went about my trip and the car done the stutter that I was talking about and when I returened, I carried out a fault code check and found this now :

2 Faults Found:

004506 - Fuel Pressure Sensor (G247)
P119A - 001 - Malfunction
Freeze Frame:
Fault Status: 01100001
Fault Priority: 0
Fault Frequency: 3
Mileage: 192505 km
Time Indication: 0

Freeze Frame:
RPM: 845 /min
Load: 13.3 %
Speed: 0.0 km/h
Temperature: 74.0°C
Temperature: 16.0°C
Absolute Pres.: 1000.0 mbar
Voltage: 14.351 V

008583 - Bank 1; System too Lean at Idle
P2187 - 004 -
Freeze Frame:
Fault Status: 01100100
Fault Priority: 0
Fault Frequency: 2
Mileage: 192505 km
Time Indication: 0

Freeze Frame:
RPM: 838 /min
Load: 13.3 %
Speed: 0.0 km/h
Temperature: 72.0°C
Temperature: 21.0°C
Absolute Pres.: 990.0 mbar
Voltage: 14.224 V


Readiness: 0000 0000

SOOOOO, I have the same fault in and also another fault has appeared lol.
Does this point more towards the sensor itself as the readings are soo far off ?

[Crasher]

If the fuel pressure is low, of course it will go lean. This shows that it is not the sensor itself but that the fuel pressure is in fact low.

[A4 Lad]

Ah ok but could the fuel pressure be THAT low and still let the car drive ? Surely the least that it can go is 0 ?
Ok so where does that leave me now ? Do you think to maybe go for the lift pump still ?

EDIT - I get you now, do you mean that the engine is indeed running lean at idle which confirms that there is not enough fuel pressure going into the engine ? I am still confused how it can be as low as -71 though ?

[A4 Lad]

Sorry, forgot to put the picture in :

[a8 tech]

look at the pressure regulator valve as mentioned and actual line pressure before the high pressure pump 6 bar is ideal

If the line pressure before the pump is ok then it rules out the pressure pump and filter

Then I would look at the mechanical valve on the rail hence g247 reading low

Note I have never found g247 defective yet but have found g410 low pressure sensor faulty on occasion but mainly the older part number recall 24m4 covered this sensor

Use this for screen dumps http://www.gadwin.com/printscreen/ so we can see

Dump at idle and then rev to limiter and dump again after the idle has settled

Your rail pressure is ok looking at the pic 51.30 bar electric pump duty cycle seems fine too but if this drops off below 48 bar ish then you have highlighted a drop off

This why I use a inline pressure gauge to rule out defective sensors and you can see what's happening to pre supply

I deal with a lot of remaps and trust me tfsi needs spot on fuel pressure

[A4 Lad]

Ok, I will go and do that now and post the results in a bit

[A4 Lad]

Ok, that is a handy program
Here we are :

At idle :



After limiter and returned to idle 1st time :



After limiter and return to idle 2nd time :



Checked after this and no faults reappeared yet ( have not road driven yet since erase )

[Crasher]

With the lambda sensor signal having told the ECU that the mixture is actually lean, I think you have an actual low fuel pressure situation rather than a misreading sensor so in the absence of a fuel pressure test gauge I would suggest changing the in tank lift pump first. Also it would be worth giving your local Audi dealer a call to see if your car is subject to or has received Campaign 24M4 under TPI 2017642/2. If the lift pump is not at fault I think the problem will be with the main pressure pump, possibly due to a worn cam/follower and this is relatively easy to inspect.

[A4 Lad]

With the lambda sensor signal having told the ECU that the mixture is actually lean, I think you have an actual low fuel pressure situation rather than a misreading sensor so in the absence of a fuel pressure test gauge I would suggest changing the in tank lift pump first. Also it would be worth giving your local Audi dealer a call to see if your car is subject to or has received Campaign 24M4 under TPI 2017642/2. If the lift pump is not at fault I think the problem will be with the main pressure pump, possibly due to a worn cam/follower and this is relatively easy to inspect.

What is the campaign for Crasher ? When I bought the car ( around 4'000 miles ago ) it had lots of timing problems which turned out to be an incorrectly timed inlet cam due to it being replaced which I assume was because of the lifter at some time rubbing through it. I replaced the lifter while I was repairing the timing to be safe. What sort of money are the pumps ?