Hi, this morning I tried to start my car, it cranked over but just won't start. Here are some facts:

1) I've verified the fuel pump ran for about 20 seconds once I turned the key to the "on" position (without actually starting the engine); so I suppose the fuel pump works.
2) I've verified the spark plugs that they actually provided good sparks;
3) The first time I tried to start the engine in the morning, it actually tried to start but could not continue; when I tried to dig deeper in the evening, it won't even "try" to start;
4) I applied SeaFoam to the fuel tank and crank case about a week ago; I only consumed a quarter of tank gas;

So, with all these said, do I have a plugged fuel system? How do I verify it? How to correct it?

Also, if someone can let me know where the fuel filter is, so that I can at least verify there is either a problem or there is no problem, I would appreciated.

Thanks in advance.

 

fogot to say that, I've changed my ECT about 4 months ago. So it would not be the ECT issue mentioned as potential in other threads. My car is a 99 A6 2.8. Thanks.

 

Ok, I've changed my fuel filter, the car still won't start. Anyone can give a hint, please?

 

Your positive it's getting fuel? I have never dealt with a no-start issue on my 2.8l (yet) and hope I don't anytime soon. But if it is like my Volvo there was a bleeder valve you could open at the end of the fuel rail, if the fuel pump is pumping fluid it will spray out of that valve when opened. The other thing is are you getting enough fuel pressure.

 

Thanks for the hint. I know it is getting fuel from the fuel filter now for sure, although I am not sure about the pressure I am getting at the engine. I am not sure how do I get pressure reading.

BTW, I've scanned the engine for code, there was nothing.

Just so I am clear, would this relate to the SeaFoam I applied?

 

I don't see how the seafoam could have hurt anything. Lets assume you have proper fuel pressure and we know the spark is good. The engine really has very little choice but to start. If I were to take a guess I would say maybe you are experiencing "the lawnmower syndrome". There are many names for it but this is the one I know it by. Basically, when the engine didn't start the other day, you flooded the engine and caused all that extra gas in the cylinder to wash away the oil on the piston rings that helps keep compression in the cylinders. Likely? Easy to check though, take out each spark plug one by one and put maybe a capful of oil down into the cylinder, put the plugs back in and try to start the car. This doesn't seem to be an issue with Audi engines but in Volvo's, this was common.

If you have a valve at the end of your fuel rail, you can buy a pressure tester that attaches to that valve.

I'm surprised no one else on here has chimmed in. Someone has go to know more about this than me.

edit: something a little more likely is your car is just plain flooded. Pull all the plugs and see if they're wet. Or try staring the car with your gas peddle all the way down, this should tell the ecu to stop injecting any fuel and open up the throttle to dry out the cylinders.

 

If I understand this correctly, the engine is turning over or it is not turning over?

 

Right, is it a crank but no start, or no crank no start?

 

The engine turns over but no start. Today I did one attempt to start the engine to see whether I am getting any fuel on the spark plug. I made sure to wait for the fuel pump stopped and then switch to ON. Of course the car did not start. I then pulled out one of the plugs and could not see anything wet. I don't suppose the fuel would evaporate that quick?

I also did a scan again on the engine using VAG-COM. There is no code. My car has always been hard to start when cold (if let sit for more than a couple of hours), maybe this is related? I recently found out a "trick" to this (before I get to this no start case two days ago), if I let the car sit for more than a couple of hours, thenif I turn the key to ON and wait for 10 seconds, the car will start OK; if I don't wait, then the car is hard to start. This has been pretty consistant.

I hope this would provide more information. Thank you for your help!

 

Take the engine cover off and locate the fuel feed line, there should be a large 17mm nut and a smaller 14mm nut next to each other, un-flange the hose then put the hose in a water bottle, turn the key to the on position and see if the water bottle is being filled with gas, if it is then fuel is getting to the motor.
If you already replaced the CTS/ECT sensor and there is no fault codes in the ECM then replace the crank/engine speedsensor.