I have a 97 A4 1.8T Quattro that doesn’t want to start. No problems with it until one morning it just didn’t want to start. I’ve scoured the other threads and can’t seem to find a solution. It cranks and fires, but doesn’t start. I pulled the line off the fuel rail and had good fuel pressure. I pulled the rail and injectors out, reconnected the injectors, cranked the motor and had a good solid pattern out of each injector. I pulled all the plugs and had good spark on each. I sprayed starter fluid on the vacuum hoses while the wife cranked the motor, no indications of a leak. Pulled the duct off the air cooler on the intake side to eliminate a clogged cooler, same for the duct between the turbo and air cleaner, no luck.

The only thing out of norm was the air filter (K&N) foam element. I pulled it out to clean it and it partially fell apart when I washed it. If some if the debris from the element got sucked into the turbo, could that cause this problem?

Assuming the spark and fuel are OK, the only things left are air or it is being electrically inhibited from starting (i.e. bad sensor) for some reason. I don’t have a VAG-COM, and my generic code reader that didn’t show any codes. Anyone have any ideas?

Thanks,
Carl

 

Oh yeh, forgot to include the obvious - I did check the timing belt, tension is good, no teeth missing, tensioner is OK, and the timing marks line up.

 

well, first off do you have the check engine light illuminated with the key in the on position, not trying to start it, but just turned on


second, did you oil the filter as well?

i would say it is
a) your ecu if you have no cel
b)maf if you tried to oil the filter and then started it... you might have killed it
c) could be the icm sensor on top of your airbox... either unpluged or dead...

 

Thanks for the response. My daughter went out to try it today and it started right up. This is actually the second time it died then cured itself within the past few weeks, so I know I still have a problem.

To answer your questions:
I do have the CEL with the key on.
I’m really not too familiar with this particular air filter – we bought this car about a year ago and the filter was already installed. Are you saying the filter should or should not be oiled?
I pulled the MAF and cleaned it with contact cleaner but couldn’t find any data in my Bentley manual as to how to test it. At a cost of $150, I hate to just throw a part like that at it without being pretty confident it is the problem.
The ICM connector is on, I checked that as well, but again like the MAF, I don’t know how (or if it is possible) to test it.

Looks as if I have something on its way to fail. The question is, what?

 

well, i used to run a k&n would oil it, but let it dry 3 or 4 days before re-installing it

 

i'm having the same problem but I hooked it up to a machine to check and see if it was a bad sensor and it wasn't. I haven't checked my fuel pressure yet though. I can smell fuel if I try to turn it over and it finally does. When it does i get a good amount of smoke out the pipes. I don't know what direction to go in now. It will start when its hot usally. But after 20+ minutes sitting it doesn't.