Original fuel filter
08-06-2017, 01:52 PM
#11
AudiWorld Senior Member
Hello Orlando,
I have quoted your comment in reference to cranking, please explain what you mean by the engine did not "crank", when someone uses the term the engine will not crank, that is referring to the starter motor not turning over the engine at all, NOT that the engine does not fire up and run, so is it that your engine cranked over, but would not fire ?
"On my 2006 audi a8 i found i had a problem with fuel delivery while driving. It seemed a bit weak at times. Next one day my car didnt crank. It sounded as if there was no fuel. I came back an hour later and it started right up. The next day i went into the eye doctor and came out only to notice it didnt crank again. It started hours later after towing."
Also that caulk will not hold, and as MP has stated, be sure the mechanisms that the actuator arms from the vacuum diaphragms are controlled by, actually move freely, and I mean the levers circled in red, not the vacuum pods, ALSO as MP stated, these will have nothing to do with you engine firing up and running, but will give you lack of power at certain rpm ranges as the 3 stage intake will not be functioning properly with the broken connector(s), or seized rod that the intake flaps are attached to.
.
I have quoted your comment in reference to cranking, please explain what you mean by the engine did not "crank", when someone uses the term the engine will not crank, that is referring to the starter motor not turning over the engine at all, NOT that the engine does not fire up and run, so is it that your engine cranked over, but would not fire ?
"On my 2006 audi a8 i found i had a problem with fuel delivery while driving. It seemed a bit weak at times. Next one day my car didnt crank. It sounded as if there was no fuel. I came back an hour later and it started right up. The next day i went into the eye doctor and came out only to notice it didnt crank again. It started hours later after towing."
Also that caulk will not hold, and as MP has stated, be sure the mechanisms that the actuator arms from the vacuum diaphragms are controlled by, actually move freely, and I mean the levers circled in red, not the vacuum pods, ALSO as MP stated, these will have nothing to do with you engine firing up and running, but will give you lack of power at certain rpm ranges as the 3 stage intake will not be functioning properly with the broken connector(s), or seized rod that the intake flaps are attached to.
.
08-06-2017, 02:19 PM
#12
AudiWorld Member
Thread Starter
It still doesnt start. It cranks strong i can hear the engine sputtering and it nearly turns completely over but not quite. I changed all the spark plugs as well. I can hear the fuel rail building pressure. Idk what else but crank sensor. Is there anything else im overlooking, like fuel pump might have a line on backwards or mis-routed! I am pretty sure it can only be assembled one way but those y fittings.
Last edited by Orlando Smith; 08-06-2017 at 02:24 PM. Reason: Add photos
08-06-2017, 03:35 PM
#14
AudiWorld Super User
I don't see a VCDS scan in any of this. It could be the crank sensor. Or it could be the coolant temp sensor. One good way to check the crank sensor is to watch the tach while the car is cranking. If it doesn't move it's your crank sensor. To check if it's the coolant temp sensor you can hold the pedal to the floor while cranking. If the car starts it's likely the coolant temp sensor.
But your best bet is to use VCDS to diagnose. You can check the reading of the coolant sensor. And you can watch measuring blocks while cranking and see if it's getting a signal. The tests above are not conclusive and I would recommend using VCDS.
But your best bet is to use VCDS to diagnose. You can check the reading of the coolant sensor. And you can watch measuring blocks while cranking and see if it's getting a signal. The tests above are not conclusive and I would recommend using VCDS.
08-06-2017, 06:55 PM
#16
AudiWorld Member
Thread Starter
im not gonna spend any money repairing that until i can get ny vehicle running. It seems to be holdin up fine. And im super meticulous...How can i access that crankshaft position sensor and when i look up the part i find a connector on a 3 to5 foot wiring, and i sometimes just find the earth magnet bottom piece that is held by 1 bolt. I hear alot of back and forth answers as i google this. When i look up the parts online i get alot of different results. I know the hubs have a abs speed sensor built in, im throwing a code for my driver rear. That design is the same as the engine speed senor/crankshaft position sensor. Which is located near the transmission belt housing bolts. I hear its accessible from the fender well. But im not sure this is the same procedure for 2006 audi a8. Am i replacing a wire or stub. Is it easily accessible. I will be using my vcds lite version on an generic off brand obd i think kkl something. I know its not perfect, but its all i got.
08-07-2017, 06:08 AM
#17
AudiWorld Super User
I followed the service manual procedure to replace mine. I recall removing the lower engine & Transmission cover, the Driver front wheel well cover and the heat shield surrounding the inboard CV Joint. The new sensor (I bought from a dealer) had the 1M or so cable. IIRC, quite a bit of the cable was bundled up when installing.
Good luck to you.
Good luck to you.
08-07-2017, 06:47 AM
#18
AudiWorld Member
+1 on the crank sensor, my 2006 did exactly the same thing the OP is describing. Changed it and have not had the issue since.
From what you describe, I disagree with you on crank sensor. May or may not be the issue, but I think it remains a possible from what you describe--based on lots of posts folks have made and ultimate solutions that worked or didn't. It's $10 or less for a can of ether as my practical diagnostic to see if motor is firing when issue arises. Just get a can and try it. You still have no real idea if it is fuel or ignition from my vantage point and need to get better tests.
Scan it with VCDS too. That comment is also still valid, and most any of the experienced guys here will tell you that fairly quickly. Gotta spend some money on tools or mechanic to maintain these in general. My guess is there is no magic cure all here, snap your fingers magic YouTube video, new revealed wisdom to be had running it around the track again the second time, or any similar ultimately wishful thinking. Need better/more diagnostics meantime.
A picture would help in what you are now adding in. I can guess what you are describing are the intake air flap vacuum actuators that switch from the long path intake tract to the short one. That will affect performance/peak power, but shouldn't affect basic running/starting. That is, it ties some to your preceding post where you mentioned it felt like power had backed off, but probably not to the no start you are struggling with just now. It is a clue though your motor likely has not been well maintained, or at least some things have gotten broken or tired. If there are vacuum leaks surrounding the actuators or elsewhere on motor, that could also relate to your symptoms. Also, even if you patched it, you likely fixed a symtom (and maybe only temporarily) but not the underlying issue. In particular, you need to see if those flaps built into the intake which the plastic arms connect to ultimately move pretty freely, or if they are binding. If binding, that's an issue and will at least need attention but maybe unfortunately a replacement intake to get back function. You can buy the arms aftermarket from gruven parts (or maybe others too??), but if mechanism is sticking that still won't cure this underlying problem. Repeating though, except for collateral vacuum line leaks (or broken off parts of intake where the flap rods pass into the inside), this actuator and intake flap linkage issue is probably not the answer to to your starting related problem either.
Scan it with VCDS too. That comment is also still valid, and most any of the experienced guys here will tell you that fairly quickly. Gotta spend some money on tools or mechanic to maintain these in general. My guess is there is no magic cure all here, snap your fingers magic YouTube video, new revealed wisdom to be had running it around the track again the second time, or any similar ultimately wishful thinking. Need better/more diagnostics meantime.
A picture would help in what you are now adding in. I can guess what you are describing are the intake air flap vacuum actuators that switch from the long path intake tract to the short one. That will affect performance/peak power, but shouldn't affect basic running/starting. That is, it ties some to your preceding post where you mentioned it felt like power had backed off, but probably not to the no start you are struggling with just now. It is a clue though your motor likely has not been well maintained, or at least some things have gotten broken or tired. If there are vacuum leaks surrounding the actuators or elsewhere on motor, that could also relate to your symptoms. Also, even if you patched it, you likely fixed a symtom (and maybe only temporarily) but not the underlying issue. In particular, you need to see if those flaps built into the intake which the plastic arms connect to ultimately move pretty freely, or if they are binding. If binding, that's an issue and will at least need attention but maybe unfortunately a replacement intake to get back function. You can buy the arms aftermarket from gruven parts (or maybe others too??), but if mechanism is sticking that still won't cure this underlying problem. Repeating though, except for collateral vacuum line leaks (or broken off parts of intake where the flap rods pass into the inside), this actuator and intake flap linkage issue is probably not the answer to to your starting related problem either.
08-07-2017, 07:25 AM
#19
AudiWorld Member
Thread Starter
Testing for CPS
So i went outside and checked the rpm guage. It did not move as i attempted starting. Ive been told that is a tell-tale sign the crank position sensor is bad.... so to clear my understanding i should remove driver wheel, engine and transmission cover, and it should be right there not too complicated to access?
