My wife drove my A6 home last night and parked it in the garage as normal. The car has under 1/4 tank and half way between the red on E and 1/4 mark. I've driven this car on the red E before with no problems. Today, we went out to start the car and it sputtered and died which it never gives me any grief. I tried to start it again and it started for a few seconds, died. I left in my truck and returned home a few hours later and tried my luck with my A6 again. It did the exact same thing. Started for a few seconds and as soon as I put my foot on the throttle, it died. I then added some cheap 87 fuel to it, it sputtered and died a few more times. I ran my code scan via torque pro to find no codes other than my deleted combi valves. After I had reset my APR tune a few times, with unsuccessful restarts, the car finally started again.

My concern is that my fuel gauge was showing about 1/8 of a tank and I can drain the tank to E with no problems in the past. BTW, Car is on perfectly flat level ground. I've never had any problems with the fuel gauge and I am able to surf every vapor of fuel out of this thing till it is on or below E. She's showing 1/8 tank.... WTH? I HIGHLY suspect it is a low fuel issue & fuel gauge is off, however, I would like some direction to rule out other things such as fuel pump, CTS, Speed sensor, and such?

Thank You for the help!

Just looking for some direction to figure out what the problem is and is not. Thanks

 

Years ago I had a similar issue on a 5000S. Turns out that over time water had accumulated in the tank and after a few years the water level was taking up quite a bit of space in the tank. The pump was sucking up water. The other possibility is that the pump is shot. A visual inspection would maybe be worth the effort. With the tank down to 1/8 or so, now would be the time to pull the pump as you wouldn't have to drain off much fuel to avoid a mess. I personally never run a tank that low ever. No matter how careful you are you will pick up dirt, water, etc over time. The closer you get to the bottom of your tank the more likely you are to suck up contamination and put it into the system. The "junk" in the bottom of your tank can also erode the pump because of the abrasives suspended in the liquid. I also don't fill up when I pull into a station and a tanker is off-loading the product I need. I go elsewhere or come back a few hours later. That tanker off-loading 8-10,000 gallons through a 4 inch hose stirs up all the junk in the underground tank and then you buy it and put it in your car.

 

I'll throw in a long shot. Years ago we had a 98 A6 2.8 that had the fuel pick up on the driver's side tank break away from the bottom of the tank. It is normally fixed to the bottom with a plastic fitting. I ran over a rock that hit the tank and broke the fitting. Tank was not compromised but the pick up floated up off the bottom. When the car got below a half tank of gas the pick up sucked air and the engine starved. Full tank, no problems. Like I said, a long shot. But maybe you have a hose that has breached and is doing something similar.

 

Thank you guys for the replies and help!

Well, I put in 2 1/2 gallons of 87. I have an APR stage 1 tune and I had selected it back to the stock position, reset with no results. I had started the car and it would idle for about 10 seconds, sputter and die every time. Finally it started yesterday after multiple attempts and after I had added the fuel, fuel gauge is now reading above 1/4 tank. I was showing no codes and as far as I was concerned, it was most likely a fuel problem, low fuel.

Well, this morning, I go to start my car fully expecting it to start up and it sputtered and died multiple times...again . I pulled off the gas cap just incase it was some sort of funky air in the tank and the car tried to start. When the car was running at idle and i stepped on the throttle, the car would die. Then it would sputter from idle to 1200 once I got it started. Then If I pushed on the throttle the revs would jump up normally. I then drove it down the street and it drives like nothing is wrong??? WTH???

Now, for the interesting comment Clancy stated. two months ago, I spun out in some snow and landed in a small ditch. I had to get a tow truck as I was stuck in a little dip off the shoulder. I wonder if something like the pick up tube got displaced. I"m a little confused as of what line your talking about as I"m not as familiar with Audi's as I am Chevy's I"m sure that I can figure it out, just need a little direction Also, I do know that when you turn the key on, you can hear the fuel pump prime on Chevys. does this occur with Audi's?

 

I waited about 45 minutes and the car starts up like there has never been a problem. No sputter from idle to 1200 rpm's, no codes, nothing??? I drove it around the block and jumped on the throttle, accelerates like it always does, quick and snappy throttle repose as normal.

I've no idea. Seems like when it's COLD and has sat all night, it starts for a few seconds and dies. Each time I start the car, it runs for a few seconds, sputters and ides. Then, once I touch the throttle, the car immediately dies. Seems like after multiple starts, once the car starts to get luke warm, it holds idle for a minute, I punch the throttle and it sputters up to 1200, then rev's past the sputtering mark, 1200rpm's, and it revs as high as I wish. Once it warms up, the car drives as if nothing is wrong?

I just cleaned the MAF, checked connections, oil, water, everything looks fine. Guess I have to wait till tomorrow to see if she does it again or not.....I hate these types of gremlins

 

Well, My volts are a sold 14.1v, cranking drops to 12.5 and back up to 14 as she starts up.

I have been searching for hours. I put vacuum to the fpr and it holds vacuum. I put the vacuum pump to the hose that feeds to the fpr and there is no vacuum, I think this is normal for this hose?

I looked into putting a gauge to the fuel line, but there is no schrader valve to hook my fuel pressure gauge to the line.

I disconnected my ECU and cleaned the terminals.

Checked fuel pump fuse which was good.

So, how does one check the fuel pressure on our cars? My torque pro does not have a way of reading the fuel pressure that I am aware of.
And what is the best way to check the fuel pump? Not sure it's the pump as it only acts up when it's cold or has sat for over 4 hours. Once the car is warm, runs fine. No codes either I also hooked up vag com light and showed no codes.

 

ECS Tuning sells a fuel pressure gauge for about $30. It is a permanent installation, requiring a cut in the rubber hose to the fuel rail.

 

I ran across this Ross Tech video recently. Don't know if it works for our vintage but worth checking out.

 

Well, she sat all night long and the car is doing the exact same thing. Car fires up for 2-5 seconds and then dies after it has sat all night long. Once I turn the car over with multiple starts,it sputters and dies, then it finally holds idle. Once it warms up after say...2 minutes, the problem is gone and the car starts like there was never a problem. WTF?

A few thoughts, bad fuel? I put 87 in because it was the only fuel offered at the station and I was almost on E. I put 5 gallons in. I considered putting a 5 gallon of 92 with some fuel stabilizer, but I don't want to have to pull the tank with 5 extra gallons in it if it is the fuel pump. That being said, How do I check the fuel pump? & how do you test the fuel pump relay?

I tried to connect via VCDS. I have the light version and it would not allow me to read the fuel pressure
I Put a vacuum gauge to the fuel pressure regulator and the car had no change to it upon start up. I put zero and 20mm/hg vacuum to the regulator with no change either way. Car just sputtered and died.

Now, how to test the fuel pump?


Thank you guys for the help.!!!