Post by target on Apr 1, 2021 10:26:26 GMT
I will start by saying that I replaced the high pressure fuel pump 8 months ago and the fuel consumption did increase notably and the performance decreased.
The car is a 2010 Audi A5 B8 3.0tdi V6 240hp s-tronic
I replaced the HPFP because it broke and sent metal shards into the whole fuel system including all 6 injectors. This was at only 120.000km.
Both the pump and the injectors were replaced with *refurbished* ones, so they are not new but I have a sheet of paper with their characteristics after being refurbished and they should be equal to the factory ones (same as new)
The whole fuel system was cleaned and the fuel pressure regulator on the rail was replaced with a new one. The rail was cleaned with an ultrasonic bath, the fuel filter was changed 2 times since (for good measure) and the in-tank and under-body pumps have been *cleaned* but not replaced.
Back to the problem.
All the "injection deviation amount cylinder x" are within +/-1.0
But I get a lambda value when idle of 0.2 which is extremely rich and dangerous for the motor oil and exhaust as far as I know.
Also VERY IMPORTANT I don't have any DTC related to mixture too rich... Why???
Another issue I have is that after letting the car in the garage for a couple days (sometimes as short as 12h) I have very very rough idle for a couple minutes after turning the car on.
In those couple minutes the high fuel pressure bounces like crazy but the requested pressure value stays the same.
Also if I turn off and on the car a couple times it seems that the problem goes away till the next day.
Even if I have a rough idle the car fires up on the first try.
If I press lightly on the throttle the problem is less notable but you can hear the motor like misfiring (still no misfire DTCs).
A very interesting fact is that after a while that the car if idling rough ALL OF A SUDDEN it is almost as I can hear a sort of click and the car is running perfectly fine
Sometimes, like in every 2 or 3 months, I get A P040100 DTC which refers to insufficient EGR flow, does this show a boost or an exhaust leak?
(That is the only DTC I get, also it doesn't trigger a CEL)
What other values should I check and what could be the problem? I will make an appointment to test the injectors and the pump.
The car is a 2010 Audi A5 B8 3.0tdi V6 240hp s-tronic
I replaced the HPFP because it broke and sent metal shards into the whole fuel system including all 6 injectors. This was at only 120.000km.
Both the pump and the injectors were replaced with *refurbished* ones, so they are not new but I have a sheet of paper with their characteristics after being refurbished and they should be equal to the factory ones (same as new)
The whole fuel system was cleaned and the fuel pressure regulator on the rail was replaced with a new one. The rail was cleaned with an ultrasonic bath, the fuel filter was changed 2 times since (for good measure) and the in-tank and under-body pumps have been *cleaned* but not replaced.
Back to the problem.
All the "injection deviation amount cylinder x" are within +/-1.0
But I get a lambda value when idle of 0.2 which is extremely rich and dangerous for the motor oil and exhaust as far as I know.
Also VERY IMPORTANT I don't have any DTC related to mixture too rich... Why???
Another issue I have is that after letting the car in the garage for a couple days (sometimes as short as 12h) I have very very rough idle for a couple minutes after turning the car on.
In those couple minutes the high fuel pressure bounces like crazy but the requested pressure value stays the same.
Also if I turn off and on the car a couple times it seems that the problem goes away till the next day.
Even if I have a rough idle the car fires up on the first try.
If I press lightly on the throttle the problem is less notable but you can hear the motor like misfiring (still no misfire DTCs).
A very interesting fact is that after a while that the car if idling rough ALL OF A SUDDEN it is almost as I can hear a sort of click and the car is running perfectly fine
Sometimes, like in every 2 or 3 months, I get A P040100 DTC which refers to insufficient EGR flow, does this show a boost or an exhaust leak?
(That is the only DTC I get, also it doesn't trigger a CEL)
What other values should I check and what could be the problem? I will make an appointment to test the injectors and the pump.