So I just had my injectors cleaned/rebuilt (one was stuck open and apparently the rest were in very poor shape, the guy that rebuilt them for me put on new seals etc but I want to tighten up the teflon seal. I bought a kit on amazon that lists a bunch of engines but not the 5.2 (thought it might still work) but the die to compress the teflon seal is very tight and I can’t slide it all the way through. How tight should these be? I realize that they hold the compression in the cylinder so I don’t want to have to remove the intake again. It’s obviously on there but I can still spin the seal with my fingers. If won’t work does anyone know what size I need to compress this properly? I can’t seem to find one for the 5.2 s6 engine only the s8 and the 4.2’s. Any help would be appreciated.
So going to be tough to really say without seeing it or the tool you used but I can say I have a Hitachi injector that came sealed and it does spin. Here is a close up picture of the seal as well.
I would also say, and this is just personal opinion, that I wouldn’t feel comfortable using seals from Amazon. Here is the link to the ones that I purchased but I only ended up needing the cages.
https://www.ecstuning.com/b-bremmen-parts/fuel-injector-seal-kit-priced-each/06e998907g~brp/
Looks like the Audi branded ones can be found here
https://www.ecstuning.com/b-genuine-volkswagen-audi-parts/fuel-injector-repair-kit-priced-each/06e998907g/?feature=alternate&source=4810653
The guy that cleaned and serviced my injectors put the seals on, he seemed to be pretty knowledgeable so I don’t think he used crappy ones the tool I bought was from amazon. I ended up using the only sizer that fit and got them as snug as I could with it. Hopefully it holds, I really don’t want to pull this intake off again
Outside of taking it back to that guy or getting a second opinion from someone else redoing the job is an unfortunate possible reality. The good news is once you get that intake off a few times it really isn’t a bad job. I remember being in your shoes and feeling the same and I’ve removed it about 6 or 7 times now since I bought the car. Initially it took me almost a whole weekend. I can now do it in about an hour or so.
Also this video helped me immensely when I had to reseal a couple on my SQ5. This video is actually for our engine though - you want to start it at 5:28.
https://www.youtube.com/watch?v=N4MVble9c3U&list=PLPVdTdtVOORhyw_dJSbHUhd08bsAVcjEJ&index=93
Hope it helps man good luck!
He told me I would need to tighten them again, I just wasn’t sure of how tight they should be exactly - I’ve never messed with direct injection injectors before. But if a bit of rotation is acceptable I should be ok. They was not much of a lip if any between the seal and the injector. I guess time will tell lol. I’m in the process of installing the intake right now so I should know soon enough one way or the other
Yeah I watched a few videos about them. Hopefully I got it right 
I’ll report back when it’s done.
So I got everything together and it’s running great at lower loads but when I try to accelerate faster I’m getting lower fuel pressure for some reason. Everything is good at idle but under load it starts to fall off and the esp warning comes on. I checked with my vcds and it idles at around 35 bar, and the low pressure system is sitting around 6 bar. Both of my high pressure fuel pumps are relatively new (within the last 2 years) and it’s both banks with low pressure. I don’t see any leaks or anything or smell gas. I even tried pulling off the new fuel filter I put on and used the old one just in case I got a defective one. I’m at a loss here, anyone have any ideas?
6bar sounds correct on the low side - which potentially rules out the in tank pump. Just out of curiosity though was that ever replaced? How many miles on it roughly? Do you know if the cam followers were replaced with the HPFPs? Also is VCDS picking up any other codes or is it just the esp light on the dash?
Do a fuel pressure log with rpm if you have VCDS.
I’ve never replaced the cam followers, just the pumps. I don’t have any maintenance history on the car until I bought it so I’m not sure about the in tank pump. From my experience with the electrical pumps (from other cars) they either seem to work or they don’t though. I’m going to pull the high pressure pumps today and inspect them to see if there is anything obviously wrong with them and check the cam followers then try to do some data logging on the low pressure and high pressure system with vcds - if I can figure out how lol
The car has just over 200,000 km’s on it right now.
Oh and I’m not getting any misfire codes or anything. One of my o2 sensors isn’t reading well but all that gas getting pumped through the system probably messed it up a bit. I’m hoping it clears up on its own - unlikely but there’s still hope lol
Both pumps and followers look physically fine, no extra wear or anything. The cam looks ok as well. I’ll have to try some data logging I guess to see what comes up.
I did some data logging on it, the low pressure side is fine everywhere. It stays around 6-6.5 bar regardless of how hard I push it, so it seems like my in tank pump is ok. The high pressure side is fine at regular speeds, but when I push it, it will often drop right off but not always. There were a few times when the recommended pressure was 100 bar and it dropped right down to 8-10. But other times it would match the required pressure. It seems like when I floor it, it just can’t keep up. Are my high pressure pumps cooked? Or is there anything else that could cause this? I am going to try to graph it but I don’t have excel on my garage computer just excel viewer. Anyways anyone have any ideas?
here are the charts, you can see on this one it got up to over 100 bar a few times but was far to low others. I think that was from accelerating slower though
This time I just punched it a few times to see how it reacted and it was very low the majority of the time
Seems like the site has been down for a few days but I was able to figure it, it was one of the solenoids on my high pressure fuel pumps. The little plunger inside was bent
Luckily I had a couple of extras around to replace it, works like a champ now. Side note also added in a jhm ecu and tcu tune after I got everything sorted, man that tune is worth the money, it pulls so much harder with it, even with my limited modifications (spacers, catback and lightweight crank pulley)