AHU conversion boost problems - SOLVED...maybe? See new post

[jhax]

Im sure you have checked but are all of your vacuum check valves pointing the correct way?

[dieseltdi]

No vacuum involved with AHU boost system. Only thing my vacuum operates is the brakes.

[dieseltdi]

OK crawled back under the van today and found oil spray at the connection from the intercooler towards the intake. Interestingly, I had originally used the rubber connector from the SAAB intercooler to make this connection between the intercooler and a length of aluminum boost pipe. When I resized the hose from the intake to the IAT bung, I changed it out to a "superior" silicone connector. Well just goes to show you that new isn't necessarily better. Apparently, it was just a bit larger than the outlet on the intercooler so that even with the clamp tightened as far as it would go, it wasn't able to hold pressure. Returned everything to its original condition. I then connected VCDS to the car and ran a few static tests from idle to about 3000 rpms to watch actual verses requested boost. Looks like I am always slightly exceeding the requested value. Anyway, I took it out on the highway and it ran great. I did manage to throw the 1550 code and go into limp mode when the boost spiked at a full throttle acceleration at over 19 psi. I was able to successfully drive with 16 plus psi of boost with no real problems. I am considering going back to my stock turbo however as the feel tells me that the custom turbo may be too spikey for the N75 and ECU. I still feel like it opens the waste gate more that it should. Anyway for now it works. Thanks for everyone who put in their 2 cents worth. David Marshall was right from the very beginning. I was originally blowing the hose onto the intake off with pressure so when I fixed that, I just made another weak link that for now is fixed. Beginning to think that the weakest link in the whole project is the loose nut behind the wheel!! Hayden