Low Fuel Rail Pressure, HELP!

[DaveyCupra]

Hi guys, I have a Leon Cupra and went the other day to get Stage 2 put on. The car was running for 2 years flawlessly at Stage 1. The mods on the car are: EVOMS intake, 3 inch exhaust system with decat downpipe and BSH catch can.

The tuner said at above 4500 rpm the map was requesting 110bar but the actual being delivered by my pump was only 90bar.

Changed the cam follower and it was mint when I took the old one out but put the new one in as a precaution. The tuner said my pump may be worn slightly internally due to the car having 56k on it.

There is no fault codes being displayed just low pressure when logged using VAGCOM.

Any ideas or advice would be great

[SteveP]

Who's remap do you have?

[PDT]

This is common at stg2 as the extra airflow requires more fuel and the pump can't meet the requested amount. I find that A session on the Dyno and carefull changes to the map should sort you right out.

Only stg2 stuff I don't get this issue with is when a twintake is fitted   whenever I am mapping stg2 with evoms or ITG, BSH intakes I eventually hit this issue and have to back off the requested boost and requested load and add a little ignition advance to compensate.

If you need any help I am always at the workshop on 01915239540

Dave.

[DaveyCupra]

 PDT,

Thank you very much 

I will have to take the car back to them on Monday and get it looked at again and show them the reply you gave me and see what they say.

[bacillus]

I would also get them to log your low pressure fuel pump that's in your fuel tank (iirc block 103) as, if it can't keep up the requested pressure, the hpfp may fail to deliver the requested rail pressure.

Also when did you last change your fuel filter as a clogged filter will affect fuel delivery to the hpfp.

[DaveyCupra]

 Bacillus,

Thanks mate, I changed the fuel filter 10k ago and they logged the low pressure system and found no supply issues (I should of said that in original post lol).

But thanks for the input 

[Statller-Stevo]

Bacillus,

Thanks mate, I changed the fuel filter 10k ago and they logged the low pressure system and found no supply issues (I should of said that in original post lol).

But thanks for the input 

If all mechanical probems check out Maybe the HP fuel return is bleeding off pressure too soon, your demand is still low very low
We fitted the RS4  trus many years ago since then lots have followed suite seems the norm now worthy a try I'd say 

[heady2010]

Rs4 trus?

[PDT]

Pressure regulator / return valve is what I assume steve wanted to type.

[heady2010]

Do you have the part number for the rs4 valve by any chance?

[bacillus]

Do you have the part number for the rs4 valve by any chance?

079 130 757

[Statller-Stevo]

Pressure regulator / return valve is what I assume steve wanted to type.

Correcto (was bladderd!) 

[Gti_Mad]

can u only buy the valve from audi ??

[bacillus]

can u only buy the valve from audi ??

TPS...

[h4rdy]

Its not easy to fit without bent and ground spanners FYI.