Fuel pump reg 2 performance issue.

[Dunkdafunk]

Fuel pressure reg 2 performance.

Hi. Got a vag com 401. Gettin the error listed above. HPFP.

Iv changed the low pressure sensor, fuel rail sensor, LPFP, and the HPFP. Im gettin 110 bar when the listed error shows with block 106 in engine group. It also shows eletrical pump number 1 at 60% when this error comes up? Im assuming the pump number 1 is the intank LPFP? Why isit not at 100%?  on block 103 i get 5.80bar from my lpfp. What isit that controls how much the lpfp and hpfp contribute? Isit the lpfp relay?

Regards,

Dunk da funk

[muff1991]

Hi mate, have you changed the fuel filter? also if you have.. is it for the correct updated bar one? you could have a blockage, restriction either in the line.. or fuel filter itself.

[Dunkdafunk]

Hi, changed the fuel filter to a bosch 1k0 201 051 c that runs at 6.6bar. i have only seen 5.8 bar on block 103 i think. Have you had experience of a pinched line from the tank? How would you test using a vag com for restricted lines?? how would you test using vag com for the voltage reg oin to the in tank fuel pump? Another thing to note is that i get a smell of fuel when the demand is high. Not sure if thats the evap carbon canister venting.

[muff1991]

you shouldn't be getting any smell of fuel.. you could have a leak somewhere? Ok, so you can rule the filter out then!

I see the below earlier, and thought it might be handy for you, so pasted it in? Have you got the HPFP with the bleeder valve?

Checking Fuel Pressure

Prerequisites:

## Ignition ON
## Engine ON (Idle)
## System voltage at least 11.0 V.
## Coolant Temperature at least 80 °C



[Select]
[01 - Engine]
[Meas. Blocks - 08]
 Group 103
[Go!]
 Field 1: Fuel Pressure (Low), Specification: 2800...7200 mbar
 Field 2: Fuel Pump Adaptation, Specification: -1000...+1000 %
Note:
## Timing chain driven engines such as the CCTA, CBFA and CCTA were phased in during model year 2008. Those engines do not use a G410 (Low) Fuel Pressure Sensor so Measuring Blocks group 103 is not applicable.


 Group 106
[Go!]
 Field 2: Fuel Rail,Pressure (actual): (A value ≈ 35 to 55% is considered normal at idle)

## A value ≈ 55% to 60% could be considered as an indication of a low fuel pressure concern

## A value above ≈ 60% to 70% usually indicates there is a failure or restriction

## A value fluctuating ≈ 35% to 95% may indicate an intake fuel pump failing ## Causes of low pressure can include: ## Damaged/restricted fuel lines

## Fuel filter issues including restricted/clogged or incorrect part number (wrong pressure relief value)

## Faulty in-tank fuel pump and/or in-tank fuel pump controller. (With critical parts, we encourage customers to use Genuine Factory parts from the dealer's parts department.).




 Group 140
[Go!]
 Field 3: Fuel Rail Pressure (High), Specification: 25.0...110.0 bar
Increase the Engine Speed while checking this value, the Pressure has to rise with the Engine Speed.


Group 230
[Go!]
 Field 1: Specified Fuel Rail Pressure (High)
 Field 2: Actual Fuel Rail Pressure (High), Specification: 25.0...110.0 bar
 Field 3: Deviation between specified and actual fuel pressure, Specification: max. 5.0 bar

## This video may be helpful:

[Done, Go Back]
[Close Controller, Go Back - 06]

[Dunkdafunk]

Thanks muff. I followed your info and it solved the issue 👏👍 the low pressure sensor is new. The intank lpfp is new. If you look at vag com adaptations on block 103 under engine and settings, for me adaptations come up with an error. Was trying to adapt it beyond -2500. When i looked at block 106 the time response from the sensor to the lpfp was over 600ms. So from this i knew there was a low pressure electronic sensor error or could have been restricted lp fuel line. Turns out the low pressure fuel sensor which was new, doesnt have easy to connect plastic fitted grooves that help the male connector click into place. Theres normally a rubber ring inside some of the electrical connectors to help stop moisture, so i literally had to push on the clip as hard as i could an now the time response on block 106 is a constant 90ms even at full throttle, with fuel pump adaptions in block 103 in the normal range. Therefore the hpfp performance fault was indeed the lpfp sensor connector. Thanks.

[muff1991]

good news @Dunkdafunk nice one on finding the issue! yes, I too have experienced the connectors being a bugger to actually connect fully due to the rubber seal!

I'm surprised this didn't show up a fault for being disconnected though. but not always does it pick up on faults! damn engine management!

I had it once too, where the block inside the connector which the pins go in to had actually moved over slightly, so when you try connecting it, it simply would only go half way down, it was off by like 1mm (god knows how I spotted it) but gently pryd it over, and fitted proper snug..

anyhow.. glad you found and rectified the issue mate. :)