HELP - Car sat for three days, won't start...

[michael66899]

My car sat in the driveway for three days without being ran and I came out today to start it and it just wouldn't fire. It turns over but won't start. First thing I did was plugged in my vag-com, no codes at all, then I unplugged the battery for awhile then plugged it back in and turned the key over for the TB adaptation. Tried starting it again and no luck. The only thing I've done since it last ran was put some new headlight bulbs in, I looked around in the engine bay for awhile too for any loose connections but no luck. Any ideas??

[Squarrl]

try a jump start?

[michael66899]

No the battery is fine, it cranks over and everything, just won't fire up, I'm going to take a closer look at everything today, any other ideas??

[TROLL]

Did you figure this out? Same situation with me right now, just trying to do some homework on it...

[James-NZ]

Check the fuel pump is running, listen inside the boot and you will hear it. Check you have gas. Check you fuse's, then check for spark.

At that point report back with your findings.

(Just went through this experience last week, 4 days after buying my A4)

[TverRus69]

agreed with James - check fuel pump fuse first. Tap on the gas when you try to start

[michael66899]

My only issue was an unplugged connector to the ignition control module on top of the airbox, easy fix and stupid mistake...

[TROLL]

Check the fuel pump is running, listen inside the boot and you will hear it. Check you have gas. Check you fuse's, then check for spark.

At that point report back with your findings.

(Just went through this experience last week, 4 days after buying my A4)

(Here's the background, if that helps at all... I let the gas get really low last week because I didnt have time to fill on my way to work. When I got out of work I went to start the car and it started a little harder than normal. Didn't think much of it, filled the tank, and went on my way. Car was fine for a few days after that, all was normal. One day went out to start it and it just cranks, but never turns over. Its like it alllllmost wants to start but it doesn't.
This is my daily driver and I haven't been under the hood in a while, so I haven't been messing with anything that might have caused this issue. Not sure how it arose but thats what I'm trying to figure out now. I'm mechanically inclined but honestly I don't really work on the Audi so its still somewhat unfamilliar to me.)

I can hear the fuel pump (i think... its pretty quiet)... just a short little prime each time the key is turned to on. This would rule out the fuel pump relay, fuse, and the pump itself from being the problem, correct?

I checked each and every fuse last night, and they all look fine. I couldn't make sense of the diagram though which is just a numbered list. Are the fuse holders numbered somehow and I didnt see? It was frigid and windy and dark when I checked the fuses so I might have missed it.

Thats as far as I got but tonight I will be checking for fuel and spark if I can get some help pushing the car into the garage. While I'm in there I'll replace the plugs at the very least.

I guess the next step after that would be to check the cam and crank sensors? Can anyone guide me on that?
And what else is there to check?

Thanks for the help... Bryan

[TverRus69]

the fuse numbers are written on the back of the panel that covers them. Make sure you got the right diagram because different b5s have fuses in dif locations. Check the ignition solenoid. Had that problem before.

[TROLL]

yeah there's a numbered list on the back of the cover... but how does that reference the actual fuse locations?

[TverRus69]

yeah there's a numbered list on the back of the cover... but how does that reference the actual fuse locations?

Well you find the fuse number designations online (i.e. fuse 3: instrument cluster), then take the panel off, look at the picture and numbers and find fuse 3 and check if its blown... i really don't understand why that is confusing (sorry don't mean to sound like an ass). As i said before tho, make sure to find the fuse list specifically for your car.

[TROLL]

There is no picture on the back of the fuse panel cover, there is a numbered LIST like I said in my last two posts.
I am sure I am missing something, but I don't see the correlation between this numbered list and the actual fuse box layout, which is what I was asking about.

[James-NZ]

Fuse box (where fuses are fitted) has numbers on it, this is what the map on the cover is referring too.

I would be inclined to think you have a blocked up fuel filter, not at all uncommon when you let the fuel run low in the tank. Check for spark first as it is easier to check than fuel.

My money is on a blocked fuel filter.

[TROLL]

Certainly a plausable idea... and something I will keep in mind.

The plan to check for fuel is to crank the car again, then pull a plug and smell for fuel in the cylinder. What would be the next step beyond that? Only other thing I could think of is to hook up a fuel pressure gauge in line, but that will obviously require tools/time.

For spark I'll pull the coil/plug and ground it to the top of the block to see if it is arcing. I did get a new set of plugs to put in while I'm doing this, its time anyway.

Sound good? Other ideas?
Thanks...

[TverRus69]

you have a blocked up fuel filter, not at all uncommon when you let the fuel run low in the tank.

Why exactly is that? The fuel filter is at the bottom of the tank anyway. This was a recent thread "is it bad to let the tank get to empty". If you are saying that low fuel level in the tank will cause all the debris and junk thats floating around clog up the filter - i disagree. Sure, the concentration of the junk might be a little higher because theres less gas to mix into but that shouldn't make a big difference. The only problem you will run into is an overheated (and possibly busted) fuel pump if you suck the tank dry.

[TROLL]

Ok so I was wrong, the panel itself does have an engraved 'map' of the fuse box on it, it was dark and cold the night before and I didn't see it.

I tested fuel and I tested spark... both seem to be there.
So where does that leave me now? Whats next? What could be keeping the car from starting at this point?

Just so you know, I tested fuel by cranking the engine for about 5 seconds, then pulling the coils and plugs, each of them were wet and smelled like unburnt gasoline.

We tested spark by pulling the coils and plugs (and fuel pump fuse) and one by one we put a spark plug into a coilpack, grounded it on the engine, and cranked it to confirm spark at each plug. This also checked out on each cylinder.

So...? WTF. Any ideas? I'd like to keep moving forward with things but I'm not sure exactly where to go from here.

Thanks for the help... hopefully I can figure this out soon and get it out of my hair since I'm trying to focus on finishing up my other car right now.

[TverRus69]

Check connections on the ICM and MAF. Visually check hoses/vac lines. I had something like this when a hose from the MAF to the IACV/TB was ripped. VAG the car if you have a cable.

[Gibbs]

same thing happened to me only in a diesel a4. Dont know if you can do it but ya can try.

Get someone to turn the car over while you loosen the fuel line bolts into to injectors. You might have a small air bubble in the fuel line. If you loosen the nut and fuel comes squirting out then its ok.

[TROLL]

If ICM wasn't connected wouldnt I not get spark?

And disconnecting fuel components while cranking the engine? That sounds like a bad idea...

[James-NZ]

Check for compression, then timing.

I your opinion did the plugs look flooded? This would also cause the car to not fire.

You have the basic necessities of combustion, now you need to make sure they are in order and mixed correctly.

[TROLL]

I'm honestly not sure what flooded plugs look like. We had cranked the motor before pulling them to confirm there was fuel, and there was... so the injectors were wet and smelled like unburnt gasoline.
They were black in color which I know isn't right... not sure if that would happen just from a few longish cranking attempts or if its something that would have happened over time.

I have new plugs I'm going to put in tomorrow and try to crank. My tech also suggested checking the ignition switch under the dash. I'm going to see if anyone in the area has a VAG-COM we can hook up to check a little deeper.

I don't have a lot of good leads here so I'm a little stressed that there may be no simple obvious solution. I'll keep going at it though and hopefully it will surface sooner rather than later.

[James-NZ]

Plugs are black with soot? Sounds like its flooded to me.

On most injected cars there will be next to no fuel on the plugs, sounds like you have too much fuel. Can you create a vacuum leak easily just to see if it will fire? Don't run it for long if it fires with the vacuum leak, basically shut it off instantly. If it fires you way too rich in fuel mixture.

Also new, un-fouled plugs might sort your problem, it could just be that the plugs are shot and not able to ignite the mixture.

I would start with the new plugs.

[TROLL]

I'm really hoping thats it. I realized that I'm not sure how old the plugs in the car are. When I bought the car at 90k miles I just took it to a friend/tech and had him do all of the 100k maintenance, but I can't be sure that plugs were included in the work that he did. I got a receipt with all of the major work, but plugs weren't on it and I dont remember buying them to give to him so that throws up a red flag.
The car now has 109k miles... and I can't say for certain how old the plugs are to be honest. Crossing my fingers thats all it is.

Now, if thats not it, is there a next step anyone recommends just so I dont potentially find myself at a standstill tomorrow? If we can get a plan b and plan c going that'd be great just so I can try to make progress on things.

Thanks again...