Hello everyone,
I'm new to this forum and of course looking for help.
I have been a mechanic for a long time, and still want to learn and expand my knowledge.
I bought a 2006 A4, 3.2 late last winter that needed a little engine work, had 98,000 kms on the clock, dealership diagnosed injectors leaking down after a hot soak test.
I brought the car home and verified the complaint, replaced the injectors with new Hitachi units along with a new high pressure sending unit, and did a full de-carbon of the intake valves.
The engine would start great once warm and also operating temp, but not so great on first start, miss-fires and runs rough, with no codes....... sometimes.
It will go into limp mode and log a P2296-006, but it seems to have to be alot colder for this to happen. I had a very close look at the harness after removing the intake again, all the way to the ECM, no problems found. I decided to have a closer look at the HPFP, removed to inspect the cam follower, which was good, but did notice some rubber fragments at the plunger seal, so I replaced the pump, also hoping the short was internal.
I ran a test on the LPFP and the run time was high, so I replaced it with a Bosch unit, along with a new fuel filter,
Also replaced the CTS as it wasn't reading correctly.
Compression test 170 psi on all cylinders, new plugs, swapped coil packs with some known to be good,
Had the dealership look at it, they checked the software level and said I had the latest version, they suggested there was a wiring problem to the HPFP, I checked the harness from the HPFP back to the ECM, did voltage and ground checks, removed the ECM to check connections for moisture entry or other, never found any problems.
I removed the HPFP to check the cam follower, it was good, but did notice some black rubber fragments on the oil side of the plunger, decided to replace it with a new one.
Went through all the adapt procedures that I could find.
Using Ross-tech HEX+CAN 18.9.0
Spring rolled around and I couldn't conclude what was wrong.
I put 7,000 kms on it last summer and it ran great, lots of power and fuel economy was good, but winter is back and I still have the same issue.
Also just replaced the n80 valve for p2404-006, tested it with a vacuum pump and it failed.
Just finished trying a readiness test, p2404-006 came up again during the test, so it wouldn't complete, no check engine light.
Also removed the PCV hose assembly and tested it for leaks, checked all other vacuum lines and have found nothing wrong.
Sorry for the long story, but I have tried everything I can think of and still can't resolve the issue,
Any help would be greatly appreciated!
I'm new to this forum and of course looking for help.
I have been a mechanic for a long time, and still want to learn and expand my knowledge.
I bought a 2006 A4, 3.2 late last winter that needed a little engine work, had 98,000 kms on the clock, dealership diagnosed injectors leaking down after a hot soak test.
I brought the car home and verified the complaint, replaced the injectors with new Hitachi units along with a new high pressure sending unit, and did a full de-carbon of the intake valves.
The engine would start great once warm and also operating temp, but not so great on first start, miss-fires and runs rough, with no codes....... sometimes.
It will go into limp mode and log a P2296-006, but it seems to have to be alot colder for this to happen. I had a very close look at the harness after removing the intake again, all the way to the ECM, no problems found. I decided to have a closer look at the HPFP, removed to inspect the cam follower, which was good, but did notice some rubber fragments at the plunger seal, so I replaced the pump, also hoping the short was internal.
I ran a test on the LPFP and the run time was high, so I replaced it with a Bosch unit, along with a new fuel filter,
Also replaced the CTS as it wasn't reading correctly.
Compression test 170 psi on all cylinders, new plugs, swapped coil packs with some known to be good,
Had the dealership look at it, they checked the software level and said I had the latest version, they suggested there was a wiring problem to the HPFP, I checked the harness from the HPFP back to the ECM, did voltage and ground checks, removed the ECM to check connections for moisture entry or other, never found any problems.
I removed the HPFP to check the cam follower, it was good, but did notice some black rubber fragments on the oil side of the plunger, decided to replace it with a new one.
Went through all the adapt procedures that I could find.
Using Ross-tech HEX+CAN 18.9.0
Spring rolled around and I couldn't conclude what was wrong.
I put 7,000 kms on it last summer and it ran great, lots of power and fuel economy was good, but winter is back and I still have the same issue.
Also just replaced the n80 valve for p2404-006, tested it with a vacuum pump and it failed.
Just finished trying a readiness test, p2404-006 came up again during the test, so it wouldn't complete, no check engine light.
Also removed the PCV hose assembly and tested it for leaks, checked all other vacuum lines and have found nothing wrong.
Sorry for the long story, but I have tried everything I can think of and still can't resolve the issue,
Any help would be greatly appreciated!
