Todd writes:
Hello Sajeev, I have a 2001 Audi TT (225hp) that cranks but wont start, not even a sputter. Thus far I’ve checked for fuel and spark and both seem to be in working condition. I verified fuel by unplugging the return line and watching fuel come out as the motor was cranked. I can hear the injectors ticking so it seems they’re working as well. I popped off a coil pack and grounded it to a screwdriver to verify that I also have spark. At this point I’m thinking the fuel in the tank has gone bad because the car has not been significantly driven in 18 months. I literally haven’t started or driven it in nine months, and when I did drive it nine months ago it was for about 3 miles. There was less than a 1/4 of a tank of gas in it while it sat for those 18 months and I just added about 3 gallons of premium to the tank with no result. There also seems to be an odd smell coming from the exhaust when I crank the car, almost like a paint remover or super glue smell. Is this bad gas? I’m really stumped here because I feel like even if the gas is bad it would at least sputter or run rough.
Any help would be greatly appreciated that you or TTAC’s best and brightest can provide. Key points:
1) Car has sat for 18 months, but ran once for three miles nine months ago.
2) Car has fuel and spark.
3) Car has no DTCs.
4) Battery was weak in the TT, but was recharged and jumped with my other car. The TT cranks strongly.
5) Odd smell from exhaust when cranking, no smoke whatsoever from exhaust.
6) Timing belt is good.
Sajeev Answers:
Quick answer, stated in a question, did you verify the actual pressure of the fuel? Having fuel in the line means nothing, you need a certain pressure to work with your car’s EFI system. So checking the pressure and verifying it’s within range enough is the first thing to do.
Todd Replies:
I did a visual and aural check, meaning I only watched the fuel squirt out of the return line while it cranked over and listened to the injectors tick. Where should I hook the fuel pressure gauge up to?
Sajeev Answers:
There’s a schrader valve (like a tire) on the fuel rail, and this is where a gauge tests fuel pressure. That’s about all I can say, because proper diagnosis requires research on VW/Audi forums, here and here. Which is technical, somewhat complicated and far too boring for TTAC’s format. I’m falling asleep just thinking about it!
So here’s the quick overview: EFI won’t work correctly with too little (or too much) fuel pressure. Since the Audi sat for a while, I recommend changing the fuel filter first. If it gets even a little better that’s a good indication the fuel system is at fault, and the fuel pump is more than likely the problem. If a new filter and pressure test turn out okay, then its time to address weak/inadequate spark condition. But I am 100% sure that fuel it your problem.
Bonus! A Piston Slap Nugget of Wisdom:
Why 100%? Because my Fox Body Cougar sat for 11 months, waiting for me to pull it’s cracked dash and failed heater core. Once I got it done, the Cat was fairly happy, even if the 1988-vintage fuel pump was already undersized (60 liters per hour, feeding 155 stock horses) for my conversion to 5.0 Mustang status (90lph, 225hp) about 11 years ago. But things got worse: idle, power above 4000rpm, and fuel economy. Then it ran flat above 2500rpm. Then it wouldn’t run above 2000 rpm. And then it just stopped running, period.
I hooked up my fuel pressure gauge only to find out its connector doesn’t work on the non-Mustang fuel rail. Fan-frickin-tastic. I replaced the filter, on a hope and a prayer, as the (running) pump shot fuel from the disconnected filter. The car did indeed sputter and stall after that, but a new pump was in order. I went to the 5.0 aftermarket, getting a pump with over four times more flow for future power upgrades. Which is awesome, except the new pump now exposed a leaky fuel rail.
After I was done cursing up a storm in my gasoline soaked driveway, I gave up and towed the Cougar to my trusted mechanic. I know when I’m beat, so here’s the Wisdom Nugget: enjoy the Audi once you fix it, but don’t be surprised if another component fails after that long slumber. It happens.
Send your queries to mehta@ttac.com. Spare no details and ask for a speedy resolution if you’re in a hurry.
I vote for fuel problems too.
When I first started the Impulse 5 years ago, it was sitting for 2 years. It’s fuel pump was shot and I replaced it with a new one. What I found in the tank was not nice, was smelly as hell and stuck in my hands for 2 weeks. Since I have about 1/4 tank, of course, it sucked all the garbage and got damaged. At that point, I ordered a Denso kit, and the problem kinda solved for 4 years.
Fast forward to 2 weeks ago, the car sat for almost a year (I had a company car) and I got the brilliant idea of letting the level go below 1/4. Again, damaged pump. With the tank down, the amount of powdered rust we found was… this time we installad a brazilian Bosch pump. Ummm…
I’d vote to remove the fuel rail, with everything in place: injectors, wires, have some helper and crank the engine. If the injectors spray ok it will be good.
Don’t worry about the smell in the exhaust. It’s the old fuel. You have a lot of barnish in your tank, that you might or not have cleaned. I didn’t, and after 5 years the goop signaling the level dissipated completely.
If changing the fuel pump, be sure to change the strainer too. It’s for sure clogged. Denso, ACDelco or Bosch or Walbro should hook you with a nice kit.
I almost forgot that I put DexronII and some WD40 in the pistons some months before starting it, just to prevent having the rings broken. The white smoke cloud it made when started was EPIC.
+1 on the fuel filter likely being a problem.
I had to change the fuel filter on my 2003 GTI with the 1.8T (Similar engine, though only rated to 180hp) every 9-10 months. I discovered this after having difficulty starting the car when it was just two years old.
Once I detected any difference in the cranking time to get it started I would replace the fuel filter and the problem would go away for a bit less than a year. I started carrying an extra fuel filter in the car, along with a pair of fresh coil packs…
Most likely bad gas. The same thing happened to an old snow-blower I bought. After purging the old gas and replacing it, it started right up.
Same here, Contrarian. Mine had sat for 8 years without use. Filled with fresh gas/oil mix, cleaned the plug, sprayed a healthy shot of ether and it fired right up and worked almost continuously for three days in heavy snow last February.
Refiners say that gasoline can be stored for six months and still be usable. Honda recommends that fuel older than 3 months not be used in its small engines. Assuming the refiners are going to be the most optimistic, I’d say the upper limit for gas shelf life (without any shelf life extender additives) is six months, and that’s only if it is stored in a full container and kept below 85 degrees F.
Since the fuel in Audi’s tank is clearly beyond its “use by” date, drain it with a siphon pump. Adding a few gallons of new gas diluted the gunked up old fuel, but it didn’t remove the problem causing compounds. If you change the fuel filter, the new one will just clog back up. Get the old fuel out, put in some new gas, then change out the fuel filter.
Obtain Vag-com (http://www.ross-tech.com/) or perhaps an obd code reader to check for fault codes
You can either buy a cheap vag com cable from ebay and use the freeware version of the software of search the forum for someone near you who already has it.
come on people, does anyone use Sta-Bil? prevents your gas from turning into nasty ‘stuff’ that damages the fuel pump!
Hallelujah! A brain!
As a marine mechanic I see this problem every spring with people who didn’t stabilize their fuel. As stated before, just because you see fuel coming out the rail does not mean you have the right pressure or volume. Also, just because the injectors are ticking does not mean they are squirting. I have seen the intake screens get gummed up preventing enough fuel from being delivered.
With boats, I tell my customers to put a bottle of fuel stabilizer in with every tank of gas. If something happens (rainy weekends) and you don’t use the boat for a while, when you do need it things are ready to go.
Nothing exotic here, IMHO. Just bad fuel. I had a 4-cycle engine powered leaf blower that I used (obviously) once a year. It was the kind that is mounted on wheels and generates quite a hurricane. After the first few seasons of use, I learned to run the thing completely out of fuel (to where the engine quite) at the end of the season. Otherwise, the next year, I would have to deal with draining the carburetor float chamber and fuel tank because it would not run on the year-old gasoline.
Unfortunately, purging this car’s fuel system of bad fuel won’t be so easy.
+1 on bad fuel.
I don’t know what exactly they are putting into gasoline these days, but I’ve had it go bad in less than 6 months sitting in my lawn mower over the summer (Seattle – spring rain, lawn grows, summer, lawn dies, fall rain, lawn grows again). Couldn’t believe it, but had the carb completely apart and couldn’t find a speck of dirt or varnish. Replaced fuel and it started right up!
I’ve had this happen twice on me in the past few years, and 20-30 years ago I had vintage (waiting for restoration) cars which I would only start a few times a year with YEARS-old gas in them and no stabilizer and never had any problems. Go figure.
I use the Stabil fuel stabilizer now in all of my small equipment gasoline – it works well in 2-cycle mix also.
ethanol
Last year I started an A6 after 8 months no problem. Stabil works. But I have been told that if you have E10 you should drop by West Marine and get a different Stabil formulation – blue colored instead of red.
I’ll know whether I got away with it again on regular Stabil when I try to restart the A6 in two weeks after 8 months.
I’ve heard that too. I’ve noticed most places in my area that sell the red stuff also sell the blue (it looks dark green to me) stuff – no need to go to Worst Marine. I’m going to use up the red stuff I’ve got, then try the blue stuff.
Easy and cheap thing to try: get a can of starting fluid (ether). Works wonders for engines that have sat for a while. Expect it to knock badly for a few seconds as ether’s octane is low. If it starts on the ether and continues to run your problem may be solved. If it starts and then stops this is a sure sign of fuel system problems, in which case a pressure check/tank drain/system flushing is in order.
I’d guess that the weak battery caused a slow crank, which with possibly poor quality fuel, didn’t allow the engine to fire right away, but did allow fuel into the cylinders. Now with a strong battery it wont fire because the plugs are fouled. I’d pull the plugs….I bet you find they’re wet with fuel.
Have you tried cranking the engine with the throttle fully opened? Often this will help expell some of the raw fuel out of the cylinders
I’d try fresh plugs and a good battery that can crank the engine as fast as possible.
…and in my experience, if he’s getting a solid stream of fuel out of the fuel line at/near the fuel rail, the car should have plenty of fuel pressure, at least to start/run at idle.
There is a lot of crud (varnish probably) someplace. I once let a nice car sit for about a year. Thankfully it had a big Holley which was easily cleaned.
We use marine Stabil in everything including the boat and lawnmower, and have no problems even with the lightly used cars.
Start replacing parts.
I bought a 96 Integra that sat for about 1.5 – 2 years before i got it. it had a full tank when parked. it would crank, but not run. After i pulled the drain plug on the gas tank and spread 10 gallons of weed killer, i refilled the tank with nice gas.
it still wouldn’t run. i pulled the injectors and listened to them click, but not spit. They had a caked screen on the inlet i cleaned with carb cleaner about 3 or 4 times. after that, they worked, so i reassembled.
the car started easily after that, and the rest was history
Something to be weary of: oil can do the same thing (granted, it takes longer). if it has been sitting in the turbos, it can conjeal and cause serious damage to the turbo bearings
In my experience with Audis, (we have had 4 in the family over 12 years) any of the temp sensors (CTS and outside air) can cause this as the ECU sets up the fuel map incorrectly.
Since your battery was dead all your previous setup values have been lost. Your car probably needs a TBA (throttle body adaptation) which you can do with a VAG.com of by turning on the ignition and not turning the starter + wait for 30 seconds. You may have pending CELs that should show in VAG.com.
The other thing that dies is the crankshaft position sensor , however you supposedly can hear injectors and you have spark so that rules that out.
Common problem with the motorcycle crowd…..Bikes sit for extended time and gum up the system. Most there recommend a product called ‘Seafoam’ to clean things up. I have no connection, but personally have used it.
Should have listened to Ned. :(
Happened to my 6.0 Briggs and Stratton lawn mower this past summer when trying to add gas about that old.
Don’t feel so bad. I let the gas sit in my 72 Fury for 8 years at one point. No way would it start. Cleaning the carb floats and fuel inlet pintle and hooking up a funnel full of gas, bam: up and running until the funnel ran dry. I dropped the tank and what came out was disgusting. I acid washed the tank and coated it with a coating product from POR-15. Flushed the fuel lines with carb cleaner and then blasted them with compressed air. A new fuel sending unit/fuel sock/fuel filter and she was running on her own!!
What to do with 6 gallons of horribly stinky fuel? Dumping it on the ground was not an option so I burned some in a can. Hell, it looked like a jet crashed in the driveway will all the black smoke. Next I tried a box fan set up in front of the burning can to add extra air. This worked well, so well I added two more cans to speed up the process. Big mistake: The heat from the can closest to the fan heated up the other two, causing the bad fuel to boil in the other two cans. The heat was incredible. It set the asphalt driveway on fire and the blades of the box fan began to melt. In the end I filtered all the remaining bad gas through a coffee filter and burned it in my work car a quart per fill up. Took awhile but I got rid of it all. Lost a couple of MPG during the “burn-off”…
For future reference, virtually all municipalities have at least one dump that will handle hazardous wastes (sometimes for a very small fee).
I’ve started and run vehicles on gas that was 2 or 3 years old without any issues.
I just revived my slumbering Merkur Scorpio after 4-5 years of not starting it. Fuel tank was about 1/2 full and I used stabil when I parked it.
After rigging up a battery, I disabled the coil and cranked it for about 20-30 seconds to get some oil moving around. Hooked the coil back up and the old girl fired right up and ran smoothly and quietly.
I drove it back and forth to work (60 miles round trip) for a few days on that 4-5 year old gas and it actually ran pretty well. Fuel mileage was off a bit, but it’s been improving after adding a few gallons of fresh fuel.
All in all, it’s been totally drama free after all those years of sitting – brakes are firm and strong, car has good power, trans shifts nice and firm…why am I selling this car again?