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.
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.
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.
< Message edited by Jeffla -- 11/28/2007 9:04:38 AM >
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.
If I understand this correctly, the engine is turning over or it is not turning over?
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, then if 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!
Posts: 5079
Joined: 2/24/2007 From: Sacramento, CA Status: offline
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 speed sensor.
< Message edited by auditech79 -- 11/28/2007 8:21:10 PM >
If you ghave better chance to start the engine after 10s key ON-your system has no residual fuel pressure. I've had this on my 4kq. There should be check valve on the fuel pump responsible for holding the pressure in the system. Not just the flow of fuel but the pressure should be tested. Where is your fuel pump located?
Posts: 5079
Joined: 2/24/2007 From: Sacramento, CA Status: offline
The other line bleeds excess pressure back to the tank, its called a return system. If the fuel pressure regulator was failing the engine would either run lean/rich, wouldn't cause the car to not start. Don't worry about how long the fuel pump charges, just worry about if gas is getting to the engine.
Is there something special I should do when I put the line back together? I mean, am I supposed to put some kind of sealer on the thread to prevent leaking? Or is there a spec for torque on that? Just wanted to make sure I do it right since it is the fuel line on top of the engine.
Working on pulling the feed line off, it is tighter than I thought.
Forgot to mention that after I changed my fuel filter and tried to start the first time (of course it did not start), there was fuel coming out of both inlet and outlet of the filter because I did not tighten it hard enough. Is it an indication of I am actually getting fuel, thinking there is nothing else in the line before the engine other than the pipe?
Ok, verified. So, there is fuel from the pump; there is spark on the plug; the plug is dry; the engine does not start.
According to AudiTech79, it is the engine speed sensor for this scenario. Where is it? Is there any write-up that I can follow?
I have a free version of VAG-COM, I believe there is one spot you can monitor the engine RPM. Of course right now if I monitor it, it is 0 RPM; but what if I monitor it while I try to start the engine? If it reads good RPM, then the engine speed sensor is good; if it reads 0 RPM, then this sensor is bad. Is my assumption correct?
Today I used my free VAG-COM to monitor the engine RPM just to verify the engine speed sensor. As I turned the key, the RPM get to 160 within a second. So the sensor is good. This made me question the way I checked the fuel line. I did not follow the instruction from AudiTech79 exactly (stupid me), as soon as I loosened the bolts for the feed line, there was fuel coming out under pressure. I assumed this was from the last fuel pump run a minute ago. But I was wrong. Today I actually disconnected the line, took a bottle and had my wife turn the key on. I realize two things:
1) there is no fuel coming out of the feed line; so the fuel pump did not run; 2) the 20 seconds of high pitch sound is not from the fuel pump, but from the engine compartment; I don't know what it is.
So now I have verified the fuse for the fuel pump, it is good; looking for the fuel pump relay but could not find it. searched the net, can someone tell me is it just behind the fuse panel? if it is, how do I take the front molding off to have access to it?
Remove the rear seat. Under it on the right hand side is a metal cover with 3 phillips head screws. Remove the cover. Under that is the top of the fuel pump assembly. There will be a couple of lines and a connector with 4 wires. Disconnect the wire connector. Have your wife crank the car and measure voltage at the connector between the two larger wires. You may have to peel back a rubber boot to see which wires are the big ones. If you have 12v then the relay and all that wiring is good and you need a fuel pump. Other wise you have a wiring/relay problem.
I tried to pull the seat bench out but it wasn't successful. As far as I know, I should just pull it up and out, but it did not want to move. Should I just pull it harder?
BTW, just my own curiosity, there is another cap under the cover of the trunck that has three screws on it. I removed the cap, and there is a two-wire connector, is it related to the fuel tank as well?
Unless its a pre 98 theres not bolts holding it in. Your just not pulling hard enough. Sometimes they stick a little. Under the seat theres a couple more covers just like that. The one you want is on the passenger side. The one in the trunk is a fuel level sender for the gauge.
Thanks dankhound. I've got the readings on the connector. The two wires on the outside are the larger ones. I turned the key to ON, the reading is 4.17V; I turned the key over, the reading is 10.85V.
I then have a couple questions regarding this:
1)I thought it would be either no reading or 12V, why it is like this? My battery may not be full because the car has been sitting here but I thought there was a voltage regulator or something? 2)Even if it is less than 12V, shouldn't the fuel pump run anyways? Maybe just a little slower?
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