W12 engine is runing bad CEL is on?

[modesim]

Hey, I bought my car a month ago and now I am start to having problems.
If I push on gas more thank 20% and if engine rpm goes more than 2200 engine looses all power and almost stalls and every time i push gas pedal it happens. RPM goes up and down.And I have no warranty so I want to try fix my self.
Does it looks like fuel is bad? or MAF? or fuel pump?
I use all time shell premium gas.
Thanks for help
now sometimes getting multiple cylinder misfire code.
I am trying drive off all gas in my tank and get a new one. I am still on same tank of gas wich started to have a problems. I am still hopping that is just gas.


Address 01: Engine
Control Module Part Number: 07C 906 018 C
Component and/or Version: D1-6.0L-AG-LEV G ª5211
Software Coding: 0000173
Work Shop Code: WSC 01065
3 Faults Found:

18331 - Please Check DTC Memory of ECU Number 2
P1923 - 008 - Implausible Signal - Intermittent
17498 - Mixture Regulation; Bank 2; Range 2: Lean Limit Exceeded
P1090 - 001 - Upper Limit Exceeded - MIL ON
17560 - Long Term Fuel Trim Additive Air; Bank 1; Range 2: System too Lean
P1152 - 001 - Upper Limit Exceeded

Readiness: 0000 1000

[jyoung8607]

It looks a lot like one of your fuel pumps isn't working. Could be a fuse, could be a dead pump.

There's a technical training doc on the Phaeton W12 engine over here. It explains about the arrangement of fuel tanks and the two fuel pumps that feed the engine. It explains that you'll have symptoms very much like yours if one of the two pumps dies. The too-lean codes are the engine trying to compensate for low fuel pressure by increasing injector open time and running out of room to adjust.

[modesim]

I do not think this is a fuel pump because this morning I tried to take out the fuse for left fuel pump and car started and stalled in couple seconds. Then I tried to take out right fuel pump fuse car started and while car parked i pushed on gas pedal and rpm reached about 4k and did not go more.

And I forgot to tell you guys when car is in park it runs good. When in gear this if I push more on gas rpm goes up and down a lot. Feels like engine is getting to much air and stalling.
thanks

[jyoung8607]

The VCDS scan you took from the ECU, take the same scan from Engine II (address 11 instead of 1) and post that here. The W12 is operated by two ECUs working in tandem. DTC 18331 is the master ECU telling you the other ECU has some codes stored as well. The master ECU (address 1) operates cylinders 1 through 6, left side of the engine (passenger's side). The secondary ECU (address 11) operates cylinders 7 through 12, right side of the engine (driver's side).

All of the intake plumbing is separated by cylinder bank (1&2 together, 3&4 together) and so it's separated by ECU as well. If you really want to look at intake issues, bear in mind most of the intake plumbing will be on the *opposite* side of the car from its cylinder bank. The throttle body and air filter and other intake plumbing feeding banks 1&2 (cylinder 1-6) are on the driver's side of the car, and vice versa. They do this so there doesn't have to be a sharp bend/curve in the intake tubing headed toward the intake valves. You'll see a diagram of it in that same training doc I linked to earlier.

If Engine II is storing too-lean codes as well, it's extraordinarily unlikely to be an intake leak. An intake leak would have to have developed in two places at once to affect both banks. It's far more likely that you have a fuel or a fuel-pressure problem.

Revving the car in park is not a good diagnostic. I've only done it once or twice, but I'm pretty sure the ECU in our cars will stop you from free-revving very high when stopped in park/neutral, I think right around that 4k you reached. I don't think you demonstrated a problem there. In fact, I think what you demonstrated that you're able to run in low-demand situations with one of your fuel pumps confirmed-dead but not the other. Fuel demand is much lower running at idle while not under load, or free revving a bit again without load. That training doc explicitly says the car will still run, but stumble under high fuel demand if one of the two is broken. High fuel demand is exactly what you have while under load, in gear, higher revs and higher throttle input.

Take out that right fuel pump fuse you mentioned and drive it around a bit and see if there's a huge difference. If the car drives about the same, that is to say it stumbles the same way under higher fuel demand, it tells you the fuel pump supplied by that fuse wasn't carrying its load and that's what you need to focus on.

[modesim]

Ok I check my car again with vag com and engine II has similar codes for too lean. And it had codes for misfiring like cylinder 1, 3, 6 and etc misfiring. I was feeling that my engine was multiple cylinder misfiring.
So now we established that i have problem with fuel not air or not like vacuum leak or maf?

I am going to try change fuel filter tomorrow (I know probably it is not going to make a difference but it is cheap and I guess nobody changed before)

I going to put fresh BP gas premium because after I got shell I started having a problem.

And then going to try play with fuel pumps again

[modesim]

I changed fuel filter and it help little bit. Now I can use little more gas and same thing happens.

If I leave car run on left fuel pump car runs same but if I leave car run on right fuel pump engine dies in 5sec.

Witch fuel pump is main and witch one is secondary?
Left pump is on driver side?

[KEEPitSIMPLE]

one pump is a transfer pump. you have vacuum leak like every other 04 vw on the road. Take to a dealer

[Phat One]

based on that information it seems like your right fuel pump is not working
Graham

[itsallbeendonebefore]

modesim,

I had this exact same thing happen to me about 2 weeks ago while driving. The cars fuel would cut off and the car would come to a stop unless I took my foot off the throttle and gave it full gas again (sort of like a pumping action(. I would start the car and the car would idle for about 20 seconds before it putters and shuts down.

The code you mentioned above read almost exactly the same at the VW dealership and it was diagnosed as a bad fuel pump. Although the VW dealership ordered two fuel pumps to replace in the event that both were out, the problematic one was the one located in passenger side.

It ended up costing me $600 including labor for one fuel pump at the dealership, (yes you can get it for cheaper) but given the circumstances, i had to have it done quick and besides i am not great at turning a wrench myself.

The car runs top after the fuel pump was replaced. I have a feeling this is one of those "problems" with our cars. Hope this helps.

Slajan

P:S: and i will echo Phat One's comment that based on your information your right pump is out (passenger side) just like mine

[modesim]

Slajan thanks for all this info.
tomorrow I am going to mechanic he knows German cars pretty good and he is going to try find problem in my car. I am going to mention what you told me.
I am pretty sure is a pump but i will pay diagnostic fee because I want to be 100% sure.

Thanks I will tell you guys in couple days what happen.

[modesim]

today i changed my right fuel pump and my car now is running fine.
So i guess it was a fuel pump
I paid for fuel pump 280 and i went to independent shop diagnostic fee 100.
I would say I fixed this problem pretty cheap.

Thank you everybody for answers and help.