Hello. I am posting here in hopes someone might have an idea of what is going on with my car. It currently cranks but doesn't start. I've been fighting with it since the start of April to get it off the driveway.
It is an 1.6TDI with 161k miles done.
It started at the beginning of April when the crankshaft sensor failed. I replaced the sensor with a new one. Car then started, we drove it up & down the drive and it seemed okay but after switching it on & off it popped a couple of errors.
P256300 - Turbocharger boost control position sensor; implausible - Permanent
00668 - +30 voltage, below lower regulation limit threshold - Intermittent
It then would start the engine, run it for approx 30 seconds, then switch off. Eventually it would struggle to even crank. And sometimes it sounded a bit weird on startup. You can see it on video here
I have then done the following.
-Replaced sender fuel pump in the tank
-Checked that there is no air in the system
-Checked the turbo actuator switch
-Checked turbo lines
The car continued having problems, so I replaced the fuel rail, after replacing said fuel rail, car will now not start at all. I even put back the old fuel rail in to see if something would change but its now in a state where it will not turn on.
I then have done the following
-Replaced the battery since the one it had was on its way out
-Quadruple checked that there is no air in the system, both in the hard lines and from and to the sender pump and the high pressure pump.
-Checked the mass air flow sensor
-Checked fuses
-Checked glow plugs and the wiring loom for it, while they don't turn on that is to be expected in a TDI engine during a warm day and the cables didn't look damaged.
Those original errors are now gone, they just poofed at some point, the computer doesn't see anything wrong with the car. Checked fuel rail pressure and its at optimal 280-300 BAR. Its worth noting the old fuel rail was displaying pressure at 420 BAR.
I am going to try running the engine tomorrow without the fuel filter, but after that I literally have no further ideas. One more thing I can think of is the car might not have ground to engine? Or somehow the injectors broke? The problem seems to be in the fact that the combustion just isn't happening for some reason.
Or maybe its still a problem with the crankshaft sensor. I was told by a friend that if the sensor don't match exactly OEM wise the car can throw a fit. And tbh I didn't check the numbers between them when fitting but they looked the same.
One last thing in case it matters, the car needs it head gasket doing, which I was planning to do in June. But I can't see how that is affecting it not starting right now.
Literally any ideas would be appreciated. Thank you.
It is an 1.6TDI with 161k miles done.
It started at the beginning of April when the crankshaft sensor failed. I replaced the sensor with a new one. Car then started, we drove it up & down the drive and it seemed okay but after switching it on & off it popped a couple of errors.
P256300 - Turbocharger boost control position sensor; implausible - Permanent
00668 - +30 voltage, below lower regulation limit threshold - Intermittent
It then would start the engine, run it for approx 30 seconds, then switch off. Eventually it would struggle to even crank. And sometimes it sounded a bit weird on startup. You can see it on video here
I have then done the following.
-Replaced sender fuel pump in the tank
-Checked that there is no air in the system
-Checked the turbo actuator switch
-Checked turbo lines
The car continued having problems, so I replaced the fuel rail, after replacing said fuel rail, car will now not start at all. I even put back the old fuel rail in to see if something would change but its now in a state where it will not turn on.
I then have done the following
-Replaced the battery since the one it had was on its way out
-Quadruple checked that there is no air in the system, both in the hard lines and from and to the sender pump and the high pressure pump.
-Checked the mass air flow sensor
-Checked fuses
-Checked glow plugs and the wiring loom for it, while they don't turn on that is to be expected in a TDI engine during a warm day and the cables didn't look damaged.
Those original errors are now gone, they just poofed at some point, the computer doesn't see anything wrong with the car. Checked fuel rail pressure and its at optimal 280-300 BAR. Its worth noting the old fuel rail was displaying pressure at 420 BAR.
I am going to try running the engine tomorrow without the fuel filter, but after that I literally have no further ideas. One more thing I can think of is the car might not have ground to engine? Or somehow the injectors broke? The problem seems to be in the fact that the combustion just isn't happening for some reason.
Or maybe its still a problem with the crankshaft sensor. I was told by a friend that if the sensor don't match exactly OEM wise the car can throw a fit. And tbh I didn't check the numbers between them when fitting but they looked the same.
One last thing in case it matters, the car needs it head gasket doing, which I was planning to do in June. But I can't see how that is affecting it not starting right now.
Literally any ideas would be appreciated. Thank you.
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