P2293 - Fuel Pressure Regulator 2 Performance

B8 A4
#1

I’ve been getting this code intermittently over the past couple months with no perceived/obvious performance loss. The CEL is cleared and it comes back a month later or so. Recently the CEL has crept up more frequently but usually during casual driving and not during WOT runs at the strip.

Most research that I’ve done points to the cam follower and/or fuel pump. However, my understanding is the design has been changed on the EA888 engine and the cam follower design ( four lobe roller) doesn’t require constant attention (I’m at ~45K km). This leads me to HPFP. While logging a variety of driving conditions I’m seeing a Fuel Rail Pressure range of 536 to 2416 psi (37 to 166 bar). Problem is I can’t seem to find “standard” values. AFR during WOT is 11.20 or roughly 0.76. MAF reading is 262.22 g/s. All reasonable for K04 tune. Short term fuel trims range from 10.2% to -7.8%.

This is all on APR’s 93 K04 tune using 94 Octane Petro Canada.
Car mods can be found here:
http://audirevolution.net/forum/index.php?topic=2129.0

Any ideas on where else I should be looking or am I missing something from the above data?

#2

Yeah that code with a B7 meant the cam follower was done. With a B8 I would be more concerned with the valve in the HPFP going bad.

No other codes like P0087?

Do you usually see the code/CEL come back after starting the engine but before it warms up?

It is probably not related but have you ever replaced your fuel filter? If not then it would be great for maintenance and to rule that out just in case.

#3

Thanks for your input “Jimmy”. No other codes that my scan tool picks up. I’ve been using DashCommand on iPhone and a wifi OBD2 scanner. My VAG-COM cable is gone to shit and I’ve been waiting for Ross-Tech to release their HEX-NET tool before I purchase another.

Over the past few months I’ve typically seen the code pop-up on the dash within the first km’s after starting the car…just recently it’s come up once after a more extended cruise. The CEL never lights up while under hard acceleration or WOT…just “typical” driving.

The fuel filter has not been replaced (unless it was done under AudiCare without me knowing). However, I have been looking for information on how/where to do it. My understanding is that the LP pump is in the tank (not easily located like the B7). Do you happen to know where the fuel filter is located for servicing?

Thanks again
Cory

#4

Also, could it be a bad sensor? I’ve heard about other 09’s with faulty HPFP’s…is it a common issue with early B8’s?

#5

That is interesting because the 4.2 S5s that I saw with bad valves in the HPFPs mostly acted up during cold starts and they would bleed rail pressure over time after shutting the engine off. Only one was noticeable during WOT runs.

There is also a not so likely chance that your fuel injectors are leaking down.

Try watching the fuel rail pressure at two different times.

  1. Start the engine cold and drive a mile but don’t let the engine warm up. then shut the engine off. Start watching the rail fuel pressure - it should stay steady for at least three to four minutes.

  2. Drive the car till the engine fully warms up then shut it off. Start watching the fuel rail pressure - it should go up fairly quickly from the heat soak of the hot engine.

If the fuel pressure goes down noticeably during the first test and/or stays steady or goes down during the second test then pull the spark plugs and smell for fuel. Another not so safe thing to do is stick a long candle/grill lighter down the spark plug holes and light it to see if the gas fumes catch fire - be very careful if you try that.

The fuel filter is considered to be lifetime on gas engines so it would not be replaced under Audi Care. It should be easy to replace. Check under the car behind the rear doors. It probably has a plastic cover over it.

#6

Thanks for that, i’ll try those tests.

Re: filter. Is there an inline filter in that location separate from the pump? Am I correct in stating that the actual pump is located in the tank?

I’ve received an extended warranty notice on injectors for my car, I wonder if one is actually faulty.

#7

I haven’t heard of any other 2009s having this issue.

The fuel filter should be inline somewhere between the low pressure pump and HPFP. Usually it is on the right side behind the rear door under the car.

The extended warranty notice is interesting. I am so glad that I got out of being a tech when I did because Audi is extending the warranty on so many things and the techs are getting screwed because of it.

#8

I had a look around the back and I didn’t see a filter. According to ECS it’s actually in the tank…that doesn’t sound very DIY friendly.

#9

That sucks. They must have changed it from the older cars. Did you see that the 2013 and newer filters were almost $300 - ouch!

Do you have the Bentley software for the B8 A4s?

#10

I got that in the mail last month too. No problems though on white lightning.

#11

No, I don’t. It looks like it’s something I’m going to have to consider.

Probably something to do with their support for E85.

#12

A small update. I continued to receive a fuel pressure too high code for months without any drivability issues. I did a little more digging and some of the tuned VW guys were also having the same issue. Someone mentioned that it was typically around 2K rpm range at the low end of the fuel pressure range. Requesting x, but measuring x+y. This is exactly the range I was seeing the CEL being lit at.

Fast forward, I just had my APR tune flashed from K04 V1 to V2. So far, so good. No Cel yet.