Hi all!
First post here and I have a really fun problem with my Audi Q7 3.0 TDI V6 2010 CCMA 180000km. I was leaving work one night and thought it would be nice to have a warm car so I went out and started it. Let it idle for about an hour (work took longer than expected) and when I came out to the car it was perfectly fine with a steady idle. As soon as i put it in gear (automatic) it got a really rough idle, stopped responding to throttle input and after about 1 minute it died and that was that. Got it towed home and now I'm scratching my head because I can't figure out what is happening. No fault codes at all, but i have communication with the ECM and if I unplug a sensor that obviously throws a code. 1 out of 10 start attempts I get a low fuel rail pressure code. The fuel rail pressure is fluctuating between 120-170 bar when cranking. Sometimes the car starts and runs good for a second or two and then loose idle speed slowly and dies. Sometimes i crank without even an attempt to fire, and sometimes it seems to fire maybe 2-4 cylinders, when cranking. I've checked flow and pressure on the lowpressure side of the fuelsystem and everything is within spec. New fuelfilter and the old one looked fine without any obvious debris in it. I've checked the pressure regulator (in the rail) and the flow regulator (at the pump) and they seem fine. If i unplug the fuel pressure sensor (in the rail) it starts for about a second (sometimes) and then dies. All of that stuff throws a code when unplugged. I noticed today that a camshaft sensor is reading around 200 rpm with only the ignition on (enginespeed is zero at this time), but when cranking the max readout is half of the crankshaftsensor, so it seems to be doing something right. If i unplug it (G40) the car makes zero attempt to start and when I plug it back in it starts firing in maybe 2-4 cylinders while cranking. I'm stumped. I don't think it's the HPFP since it sometimes run good for a very short period of time. I don't find any other sensor with a weird readout (temperatures and pressures). Those rare moments I get it to run it dies immediately if I crack open a fuel line to the injectors. I need any input I can get cause it's starting to suck having it parked with no idea how to proceed...
Kind regards and thanks in advance
First post here and I have a really fun problem with my Audi Q7 3.0 TDI V6 2010 CCMA 180000km. I was leaving work one night and thought it would be nice to have a warm car so I went out and started it. Let it idle for about an hour (work took longer than expected) and when I came out to the car it was perfectly fine with a steady idle. As soon as i put it in gear (automatic) it got a really rough idle, stopped responding to throttle input and after about 1 minute it died and that was that. Got it towed home and now I'm scratching my head because I can't figure out what is happening. No fault codes at all, but i have communication with the ECM and if I unplug a sensor that obviously throws a code. 1 out of 10 start attempts I get a low fuel rail pressure code. The fuel rail pressure is fluctuating between 120-170 bar when cranking. Sometimes the car starts and runs good for a second or two and then loose idle speed slowly and dies. Sometimes i crank without even an attempt to fire, and sometimes it seems to fire maybe 2-4 cylinders, when cranking. I've checked flow and pressure on the lowpressure side of the fuelsystem and everything is within spec. New fuelfilter and the old one looked fine without any obvious debris in it. I've checked the pressure regulator (in the rail) and the flow regulator (at the pump) and they seem fine. If i unplug the fuel pressure sensor (in the rail) it starts for about a second (sometimes) and then dies. All of that stuff throws a code when unplugged. I noticed today that a camshaft sensor is reading around 200 rpm with only the ignition on (enginespeed is zero at this time), but when cranking the max readout is half of the crankshaftsensor, so it seems to be doing something right. If i unplug it (G40) the car makes zero attempt to start and when I plug it back in it starts firing in maybe 2-4 cylinders while cranking. I'm stumped. I don't think it's the HPFP since it sometimes run good for a very short period of time. I don't find any other sensor with a weird readout (temperatures and pressures). Those rare moments I get it to run it dies immediately if I crack open a fuel line to the injectors. I need any input I can get cause it's starting to suck having it parked with no idea how to proceed...
Kind regards and thanks in advance