Vehicle: 99.5 A4 TQM, 127k miles

The car was running fine with no CEL. After sitting for less than 48 hours I tried to start it. It turns over but does not even attempt to start. As I had just changed the headlight bulbs, I assumed that I bumped a connector. Checked and found nothing.

I purchased VAG-COM and ran an auto-scan. The only code that came up was an interior motion sensor code, which I cleared. Tried to start again, same result. I have tried to check for codes again and still do not find any.

I used the same VAG setup on a VW to make sure it wasn't the software, and it read codes which I know to be true.


What would suddenly make an A4 not start, but not throw a code?

 

Check your fuses, make sure the engine is getting fuel and spark, go from there.

 

or at least some of both. I pulled the fuel line and it dripped some fuel, so I put it into a bottle and turned the key on for a couple seconds. Some fuel sprayed into the bottle.

I pulled #1 and #2 plugs to see how they looked. There is a lot of oil leakage around the valve cover, and it appears it's made its way down into the spark plug holes as well. I grounded out one of the plugs and cranked the motor. It sparked.

I pulled the timing cover back and the timing belt is still on the cam gear and seems tight.

If I've got spark, fuel, no codes, what's the next step?

 

Engine coolant temp sensor or maybe maf. Unplug them (one at a time) and try to fire it up. If either one is bad it can cause you to be way rich on a cold start. Just guesses. Definitely clean all the plugs first. When you changed the passanger side headlight, you didn't remove the airbox did you?

 

I just had the same problem... ended up being the ignition module... Try unplugging that and pluggin it back in... I ended up having to buy a new one... my car was also not turned on for about 2 weeks...

 

The car will start without maf or temp sensor (individually) under normal conditions?

I removed the top half to gain access to the back of the headlight.

 

I know that the car will start without the MAF plugged in... but your car will either run rich or lean... not good

 

The evap check valve over the air box has a large hole in it. Didn't find anything else.

 

Youd run rich with the maf unplugged, but not as rich as you might if the maf were bad and same w/ ects. The point isn't to start it up with those things unplugged and drive around, but just to see if it starts at all. That check valve on the airbox is known to rott out on the bottom, but it's not the reason for the no start. Do a throtle body alignment with vag com for ***** n giggles.

 

Can I pull that grommet out through the top of the airbox, or do I have to rip the whole damn box apart to get to the connector? Either way it will have to wait until it's light out and I get some more time to mess with it.

I did disconnect the temp sensor with no positive result.

With everything connected it did kick over a few times like it was trying to start, which is more than it has been doing. It seemed to want to start right after I had held the throttle open for a few seconds. I did notice that the tach doesn't really move, but wasn't aware if this was normal or not when turning at starter rpm.

I can do the TB alignment tomorrow as well.


Thanks for your help so far. I was really hoping I'd be rewarded for buying VAG-COM and it would give me a code. It's never that simple though.