HardHitter

iTrader: (4)

Alright, I'm cleaning up my 7 and getting it prepped for sale and I have one last thing I need to check out before putting it up on the market and it's my boost.

Here is what has happened, the car had it's FPD replace along with vac hoses. During that replacement, 3 solenoids were broken and then replaced. As I test drove the car and it runs perfect boosts fine etc. Then one day when I was driving and I went to merge onto the freeway, I WOT and my boost stays around 1-2psi all the way to redline. I try it again and again 1-2psi. I just cruise staying out of boost until my exit is coming up and I down shift and WOT and my car pulls hard as normal and the boost is normal.

It has done this almost 2-3 times the past two weeks and I can't figure out what this problem could be. I did a search and I've came up with vac hoses, check valves, ecu, etc.

I think the first thing I should do is reset my PFC (I am running it's base map). Since working on the car, the ECU hasn't been reset, could this cause the problem if the PFC does not get reset when putting in different solenoids?

I'm going to reset it tomorrow and go through the idle reprogram again. The only problem is I won't know until it happens again and if it will happen again, it just happens randomly and this is something I want to eliminate before putting up on the market because how bad would it be if someone is test driving it and it happens, yea, not good lol.

Any other options/things to check would be welcomed for discussion so I can check them and narrow down the problem.

Goukid2

sounds like my problem. Check to see if your butterfly in your Y pipe is sticking. The one going to the secondary turbo.

sereneseven

The PFC does not have any kind of feedback circuit from the solenoids so it doesn't have any way of knowing if you have changed them or if they are working.....so just to rule out out one option for you NO the ecu does not need to be reset if you changed them.

HardHitter

iTrader: (4)

Yea it's just a really weird problem. I never really boost when I am driving around on the streets, only when I'm on the freeway is when I'll boost or do a WOT run.

HardHitter

iTrader: (4)

Bump to help out me and Goukid

DaleClark

iTrader: (55)

Goukid has a good point - if there's a problem with the double throttle, that's a big power drop. If you have a flaky check valve, that can also cause all kinds of weirdness - I sell Viton replacement valves that work great and are cheaper than stock if you'd like to rule that out.

Dale

209FD

iTrader: (2)

It does sound like something is sticking, if you have an air compressor get a blow gun and connect it to the turbo actuators and wastegate actuator and make sure the arms move out. Also double check all the solenoids and hose routing, an easy way to do that is take a 9v battery and touch the solenoid contacts. You should hear it click. If its sticking take some silicone spray lube (use only silicone lube because wd40 or anything else will eat the valve) and spray it in the inlet, and then take a toothpick or something like that and stick it in the inlet gently till you feel it free up.