Chasing a few codes...can you help??

[djhemmen]

I've been chasing a few codes since January of this year and have been able to get rid of a few of them with a couple parts but cannot seem to get rid of the P310b code and the P0300/0303 codes!?
Here's my Vag scan from January 2016 when the Random/Multiple Cylinder Misfire Detected codes started:

3 Faults Found:

000768 - Random/Multiple Cylinder Misfire Detected
P0300 - 008 - - Intermittent - MIL ON
Freeze Frame:
Fault Status: 10101000
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 209510 km
Time Indication: 0

Freeze Frame:
RPM: 1325 /min
Load: 45.9 %
Speed: 0.0 km/h
Temperature: 30.0°C
Temperature: 18.0°C
Absolute Pres.: 1010.0 mbar
Voltage: 14.097 V

000771 - Cylinder 3
P0303 - 008 - Misfire Detected - Intermittent - MIL ON
Freeze Frame:
Fault Status: 10101000
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 209510 km
Time Indication: 0

Freeze Frame:
RPM: 1313 /min
Load: 44.7 %
Speed: 0.0 km/h
Temperature: 31.0°C
Temperature: 18.0°C
Absolute Pres.: 1010.0 mbar
Voltage: 14.097 V

004688 - Fuel Level too Low
P1250 - 008 -
Freeze Frame:
Fault Status: 01101000
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 209510 km
Time Indication: 0

Freeze Frame:
RPM: 1283 /min
Load: 45.1 %
Speed: 0.0 km/h
Temperature: 31.0°C
Temperature: 18.0°C
Absolute Pres.: 1010.0 mbar
Voltage: 14.224 V


Readiness: 0000 0000

I replaced the coil packs with the red tops from ECS Tuning and Autolite XP Iridium/Spark Plugs as well as did a carbon cleaning on the valves 3 weeks ago to try to fix the rough idle the car is experiencing. The car has so much more power and is much more responsive now but is hard to start after it has been sitting overnight. During the carbon cleaning I did remove the HPFP and checked the cam follower and noticed only minor wear so I did not replace it (my car is stock). Before I replaced the coil packs/plugs I swapped out coils/plugs 2 and 3 but the error continued to stay on Cylinder 3.

I noticed on my last 2 fuel fill ups that my gauge only showed 3/4 of a full tank so I am wondering if my P310B code is due to a failing LPFP or the LPFP controller? I replaced the LPFP sensor on the HPFP about 9 months ago as well as the PCV to the latest revision around the same time.

Here's the scan from today:

3 Faults Found:

012555 - Low Pressure Fuel regulation
P310B - 004 - Fuel Pressure Outside Specification - MIL ON
Freeze Frame:
Fault Status: 11100100
Fault Priority: 0
Fault Frequency: 4
Reset counter: 255
Mileage: 219563 km
Time Indication: 0

Freeze Frame:
RPM: 1353 /min
Load: 49.4 %
Speed: 0.0 km/h
Temperature: 27.0°C
Temperature: 24.0°C
Absolute Pres.: 1010.0 mbar
Voltage: 14.224 V

000768 - Random/Multiple Cylinder Misfire Detected
P0300 - 008 - - Intermittent
Freeze Frame:
Fault Status: 00101000
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 219563 km
Time Indication: 0

Freeze Frame:
RPM: 1275 /min
Load: 51.4 %
Speed: 0.0 km/h
Temperature: 28.0°C
Temperature: 23.0°C
Absolute Pres.: 1010.0 mbar
Voltage: 14.224 V

000771 - Cylinder 3
P0303 - 008 - Misfire Detected - Intermittent
Freeze Frame:
Fault Status: 00101000
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 219563 km
Time Indication: 0

Freeze Frame:
RPM: 1208 /min
Load: 45.1 %
Speed: 0.0 km/h
Temperature: 36.0°C
Temperature: 22.0°C
Absolute Pres.: 1010.0 mbar
Voltage: 13.970 V


Readiness: 0000 0001

Any help is greatly appreciated so I can get this thing fixed and running right! Thanks.

[cdh9400t]

Your p310b code could be the in tank low pressure fuel pump, or fuel filter since they do have built in fuel regulators. If by chance that lpfp is failing the injectors may not be getting enough fuel causing miss fires.

[djhemmen]

Your p310b code could be the in tank low pressure fuel pump, or fuel filter since they do have built in fuel regulators. If by chance that lpfp is failing the injectors may not be getting enough fuel causing miss fires.

Thanks for the quick reply. I forget to mention that I replaced the fuel filter with a Mann filter from ECS at the same time I replaced the coil packs/plugs.

I just ran a VCDS scan on [01-Engine][Meas Blocks - 08]Group 106, field #2 and it appears my LPFP is on its way out as it is above the 50% duty cycle where the below link says it should run at idle:

Address 01: Engine (8E0 910 115 P)

14:04:29 Group 106
49.61 bar Fuel Rail Pressure
83.1 % Electrical Fuel Pump 1
Electrical Fuel Pump 2
655.35 s Time

http://forums.ross-tech.com/showthre...r-Audi-A4-2-0T

[djhemmen]

I just noticed that the P310b showed up the same day I put everything back together after removing the intake manifold for the carbon cleaning, removing the oil filter housing/oil cooler to replace the leaking gaskets, and removing the HPFP to make it easier to remove the intake mani and also check the cam follower. When I removed the HPFP I messed up the small hose that connects the HPFP to the hard fuel line and replaced it with universal fuel line from the local auto parts store. I don't see any kinks or leaks in that hose but could that be the reason for the P310b. It does seem it is something that I did since the code appeared the same day I put it all back together after I did the work.

[allstock]

14:04:29 Group 106
49.61 bar Fuel Rail Pressure
83.1 % Electrical Fuel Pump 1
Electrical Fuel Pump 2
655.35 s Time

Your lpfp above 50 at idle doesn't mean that it's on the way out at all, but it's not brand new....More misinformation.

If that is your reading @ idle and full temp then, yes it's slightly weak for some reason. @idle your rail pressure looks spec. I'd check measuring block 103 to see that you are outputting high 4's to 5 at full temp.