hi,
due to high pressure fuel pump failure i had to rebuild the fuel system on my 2012 audi a4, 2.0 tdi (CAGA engine code). This was done 2 years and 70.000km ago. i got new injectors and high pressure fuel pump from https://www.diesel-technik-biberach.de
All other parts was just cleaned with gasoline, that includes bot fuel pumps (intank and transfer pump).
Fuel filter was changed after 1000km and than again after 5000 km if any metal particles was still in the fuel tank.
New codes of the injectors was inserted into the ECU using VCDS.
When timing belt was installed fuel pump was in perfect timingf but after i removed the pin and rotate the crankshaft 3 times fuel pump was half a millimeter off and I didnt bother.
Car from the begining had throubles to start, sometimes just every 10th start was problematic, sometimes everone. It was the worst if it stayed uphill as if fuel was going back to the tank.
Othervise it runs smooth, has normal consumption, has normal power and doesnt smoke. injectors leake off test are also ok, and newer in 70.000km was any throuble code stored in the ECU.
first I thought that fuel just leaks back to tank and firstly I changed this plastic valve system before 2nd fuel pump. I don't really understand what it does, anyone knows?
since it didn't help I tried with new 10bar pressure retainer on the injector return line (only comes as a complete hose part).
It helped for about a month, then this part fail and start leaking on the retainer itself and bought new one but Bosch this time. Long crank stayed.
Since I was tired of waiting up to a 7 second for the car to start i made a simple timer that activates when car is unlocked and sends 12V to the fuel pump for 5 sec. This way engine starts right away.
It is fine with me this way, but my concern is that something is wrong either with high pressure fuel pump or injectors or fuel pressure valve on the rail or fuel metering valve on the pump itselg and that car could die any time.
below is a diagram what was changed, what was cleaned.
ibb.co
and log for injection deviation after 70.000km
Help with diagnostic to the cause would be much apriciated, since I got all sorts of sugestion any mostly all involve to much $$$. They sugest trying to change 2nd fuel pump (500€), rail pressure valve (250€), some even sugested new injectors and or pump.
due to high pressure fuel pump failure i had to rebuild the fuel system on my 2012 audi a4, 2.0 tdi (CAGA engine code). This was done 2 years and 70.000km ago. i got new injectors and high pressure fuel pump from https://www.diesel-technik-biberach.de
All other parts was just cleaned with gasoline, that includes bot fuel pumps (intank and transfer pump).
Fuel filter was changed after 1000km and than again after 5000 km if any metal particles was still in the fuel tank.
New codes of the injectors was inserted into the ECU using VCDS.
When timing belt was installed fuel pump was in perfect timingf but after i removed the pin and rotate the crankshaft 3 times fuel pump was half a millimeter off and I didnt bother.
Car from the begining had throubles to start, sometimes just every 10th start was problematic, sometimes everone. It was the worst if it stayed uphill as if fuel was going back to the tank.
Othervise it runs smooth, has normal consumption, has normal power and doesnt smoke. injectors leake off test are also ok, and newer in 70.000km was any throuble code stored in the ECU.
first I thought that fuel just leaks back to tank and firstly I changed this plastic valve system before 2nd fuel pump. I don't really understand what it does, anyone knows?
since it didn't help I tried with new 10bar pressure retainer on the injector return line (only comes as a complete hose part).
It helped for about a month, then this part fail and start leaking on the retainer itself and bought new one but Bosch this time. Long crank stayed.
Since I was tired of waiting up to a 7 second for the car to start i made a simple timer that activates when car is unlocked and sends 12V to the fuel pump for 5 sec. This way engine starts right away.
It is fine with me this way, but my concern is that something is wrong either with high pressure fuel pump or injectors or fuel pressure valve on the rail or fuel metering valve on the pump itselg and that car could die any time.
below is a diagram what was changed, what was cleaned.
Screenshot-20230125-193932-Gallery hosted at ImgBB
Image Screenshot-20230125-193932-Gallery hosted in ImgBB
ibb.co
and log for injection deviation after 70.000km
Help with diagnostic to the cause would be much apriciated, since I got all sorts of sugestion any mostly all involve to much $$$. They sugest trying to change 2nd fuel pump (500€), rail pressure valve (250€), some even sugested new injectors and or pump.
