Car not running well/no codes

[Chung]

Well the inevitable happened and my RS6 left me stranded on the way home from Christmas as the parents. I was on the freeway about to do a pass and when I pressed the gas the car hesitated and almost died. At first I thought the torque converter gave out since I could hardly get any power down but when I went to start it to get it on the tow truck the car barely started.

I towed it to my sister's and when I checked the codes, as crazy as it sounds, there are no faults for the engine or the transmission. It takes a lot to get it started and you have to press the gas to keep it going. Smells really rich. My guess is the fuel pressure regulator but it is really a guess.

Any thoughts from the experts here?

[as350]

Could be several things. But one experience of mine comes to mind after I did some work that required the removal of the air filter box. I didn't re-seat the MAFs fully into the turbo intakes and after a couple of days it did the same thing as yours. Ran really rough.

I hope it's going to be something as simple as that.

[Bigglezworth]

First thing that I would be looking at is a bad TPS (Throttle Position Sensor). Second to that I would be a fuel pressure regulator. Look for obvious things with your hoses not being sealed and not leaking also. Check things out yourself by removing the airbox, removing the MAF's from the airbox, and then seating them in to the downpipes. You can run and drive this car without the airbox on it as long as you address the sealing of the MAF's. Once you get the car started, check for vacuum leaks. Wiggle around the MAF's. They should drastically change your idle if air is escaping past the seal and in to the inlet pipe. There shouldn't be a strong fuel smell obviously.

[ttboost]

Probably out of gas...or a clogged fuel filter...nearly everything else will give you a code...Check fuel system first...

[DHall1]

Fuel starvation

Check fuel pressure first

Then work back from there to the tank


Probably out of gas...or a clogged fuel filter...nearly everything else will give you a code...Check fuel system first...

[Bigglezworth]

I wanted to state the obvious about lack of fuel based upon your description, but then you cite there being a strong fuel odor. Can't have that when you have no fuel. Car requires the 4 basics to run. Fuel (open gas cap, rock car, and listen for slushing sound - do not rely on fuel gauge), air (self explanitory), compression/vacuum (operate in a pair), and finally spark. All the items that supports transporting or monitoring any one of these items should toss an error code as ttboost mentions.

[Chung]

I did check the airbox just to see if it had popped off or something. My last fill up was 78 miles ago so there is gas, who knows about the quality of that gas. I replaced the fuel pump in the tank when I did Audi replaced the gas tank but I didn't replace the high pressure tank. The fuel filter has unknown miles on it so replacing both that and the spark plugs sound just like good maintenance things.

Hopefully I can get the parts before the new year and go down and work on it over the holiday.

Seems so odd to me that the car barely starts let alone runs and there are no codes.

[Bigglezworth]

If the fuel odor is strong under the hood, the I would also check fuel pressure lines (both supply and return) for leaks. Leaking hose reduces pressure to the fuel rail and will create fuel starvation which your description supports.

[Avus-RS6]

Sorry to hear of your trouble. Some good advice has already been given. My tidbit, try un-plulgging your MAF's and see if it runs, I've gotten many broke down B5's to run temporarily by doing this. It won't solve your problem but will allow you to move your car around easier until it's fixed.

Personally, I would have my car towed to Redmond European or U-Audi and let them fix it. (My car goes to AMD but it's 'SPECIAL') ;-)

Good luck!

[Corbett]

I can almost guarantee he just has a major boost leak. Try checking your intercooler hoses. Unplug your mafs and if your car idles fine it's a hose that has popped off somewhere.

[Chung]

Sorry to hear of your trouble. Some good advice has already been given. My tidbit, try un-plulgging your MAF's and see if it runs, I've gotten many broke down B5's to run temporarily by doing this. It won't solve your problem but will allow you to move your car around easier until it's fixed.

Personally, I would have my car towed to Redmond European or U-Audi and let them fix it. (My car goes to AMD but it's 'SPECIAL') ;-)

Good luck!

Seattle was outside of my 100 mile towing :) Interesting last time my hose popped off it actually ran fine still just not too much power. When that happened I replaced all the hoses with silicon hoses and the constant torque clamps. It would be great if the hose coming off is the issue.

My sister happens to have a lift as well as a garage to park my car so I will get the car on the lift and check things out when I go back south. The car needs new plugs, fuel filter, intercoolers, and little service things that I can do while I am down there.

Also thanks for coming to the rescue everyone. This board is a big help for me and many others.

[DHall1]

Your sister has a lift in the garage? Get out

Source up a fuel pressure gauge test kit before you go down. There is a nipple/port on the fuel rail to tie it in. That should be the first check. Then go from there.


Seattle was outside of my 100 mile towing :) Interesting last time my hose popped off it actually ran fine still just not too much power. When that happened I replaced all the hoses with silicon hoses and the constant torque clamps. It would be great if the hose coming off is the issue.

My sister happens to have a lift as well as a garage to park my car so I will get the car on the lift and check things out when I go back south. The car needs new plugs, fuel filter, intercoolers, and little service things that I can do while I am down there.

Also thanks for coming to the rescue everyone. This board is a big help for me and many others.

[ttboost]

Your sister has a lift in the garage? Get out.

My wife has a lift in her garage...I get to use it too...

[Bigglezworth]

My wife has a lift in her garage...I get to use it too...She has a different garage than you??

[Chung]

Yeah, she bought a new house that had a crazy garage. The house has a two car garage too. Her husband has a Packard that he works on but pretty much it is just my dad's car there. It is nice because there is so much room to store cars there and they don't mind me using it.
14533

Something like this?
http://www.harborfreight.com/fuel-injection-pump-tester-92699.html (http://www.harborfreight.com/fuel-injection-pump-tester-92699.html)

[DHall1]

That's awesome! Good job sis

Yep, you can pick one up at autozone too


Yeah, she bought a new house that had a crazy garage. The house has a two car garage too. Her husband has a Packard that he works on but pretty much it is just my dad's car there. It is nice because there is so much room to store cars there and they don't mind me using it.
14533

Something like this?
http://www.harborfreight.com/fuel-injection-pump-tester-92699.html (http://www.harborfreight.com/fuel-injection-pump-tester-92699.html)

[ttboost]

Pretty sweet setup your sis has Chung...My house has 2 car up, 1 car under and I just built a 6 car addition, 3 doors in front, 1 in the center in the rear...14' ceilings...radiant heat in the floor... handy for doing stuff...Can't wait to figure out what my new project is...

[905084]

Unplug the MAF's for starters...easy and cheap.

[hahnmgh63]

Rian, when you head down south I have a fuel pressure tester set. Not sure if there are all the fittings but you can probably make it work. Any other tools you need to borrow let me know. I can probably bring them into work and meet you somewhere off I-5 so you don't have to come out and listen to the neighbors with Banjos.

[Chung]

Thanks Mark. I am going to take the train down so I will probably just stop at an Autozone when I get there. I tend to buy the tool I need and leave it for my brother inlaw to help out getting more tools.

It is amazing some of the garages the members have here. Mark's garage has the trifecta, space, tools, and someone who knows what they are doing.

ttboost, if you need a project I can send you my car, it needs a manual transmission (maybe more) :)

[ttboost]

Ha..you aren't the first to ask...

[kismetcapitan]

I'm putting my money on boost leak. Never had this happen to my RS6 but it happened ALL the time with my '91 Skyline GT-R and the symptoms were identical. The MAFs read X amount of air and injects the requisite amount of fuel, but with the air leaking and not reaching the engine, you end up choking the engine with too much fuel and it will barely run.

[Corbett]

Yes. this exact thing happened to me while I was 600 miles from home. I gunned it and car died. Would start back up and then die. Could only get car to run if I played with the gas pedal. Got to a gas station. Car smelled like fuel. Found upper intercooler hose was completely off the intercooler. 5 min fix. Hope it's as easy for the OP

[ttboost]

I've had upper IC hoses come off (usually at the track and I can't get them back on)..Car runs and drives fine, just won't boost...

[Chung]

And the winner seems to be the fuel filter. I checked the hoses and they were all on snug. Replaced the fuel filter and it started right up and ran great for the last 30 or so miles. Next up the 200 mile journey home.

Thanks for all the help, the people here rock.

[DHall1]

Winner winner chicken dinner!

Hats off to ttboost as well. He hit it too.

Glad it was a simple repair.


Fuel starvation

Check fuel pressure first

Then work back from there to the tank

[Bigglezworth]

Good news. Remain unclear on why you would have a strong fuel odour with a poor performing fuel filter, but as long as you've fixed the problem.

[as350]

Glad you found the cause and that it was a simple fix.

[Chung]

Good news. Remain unclear on why you would have a strong fuel odour with a poor performing fuel filter, but as long as you've fixed the problem.

I am not sure about that either. Maybe my brain was making things up.

I really hope the problem is fixed. When I got there yesterday the car would only sort of run and I coasted it on to the lift. After the fuel filter replacement it ran like a champ again.

Time to add the fuel filter into the things I regularly make sure I do. It is not the easiest thing to replace for the mechanically challenged like myself but by far not the hardest part to replace on the car.

[G2]

And the winner seems to be the fuel filter. I checked the hoses and they were all on snug. Replaced the fuel filter and it started right up and ran great for the last 30 or so miles. Next up the 200 mile journey home.

Thanks for all the help, the people here rock.

Can't ask for anything "better". Replace my fuel filter every year-- it's far too small. My old Scirocco has a filter 2-3X bigger......

[G2]

I am not sure about that either. Maybe my brain was making things up.

I really hope the problem is fixed. When I got there yesterday the car would only sort of run and I coasted it on to the lift. After the fuel filter replacement it ran like a champ again.

Time to add the fuel filter into the things I regularly make sure I do. It is not the easiest thing to replace for the mechanically challenged like myself but by far not the hardest part to replace on the car.

I think you were right: when there's not enough fuel to support combustion it gets pumped out the exhaust. Hence the fuel smell. What some call a lean mis-fire (for a barely running engine). Took me awhile to figure that out in the real world, but tech school helped. Too rich or too lean= gas smell.

Fuel filter replacement is a pain even on a lift. Disconnect it at the fuel pump and remove filter and the supply hose that crosses over the fuel tank. Replace the hoses with new if hardened to ensure good sealing and hose splitting.

It's likely the fuel pump is on it's way out, and if not, the "dead-heading" of the pump sure speed that process up. The pump to filter pressue is excessive. Consider replacing the filter again in 3-6 months as the residual contamination will likely stark packing up the new filter. I noticed this in my car during it's first servicing.

[JSRS6]

And this is why I'm going to replace my external with a Bosch and mount it differently under there to ease future filter changes.

[Avus-RS6]

Great thread, glad you go your car going again! I'm going to have mine changed yearly. I tend to do 21-22 gallon fill ups so I know mine will need it.