Vacuum lines re-done in silicone. Test drove car and boost normally at 4500, then at switch over, drops to between 6-7 psi and stays there.

It appears to me that the secondary turbo, isn't making any boost and is there a specific check valve or other item I should check first.

Any help is greatly appreciated.



Andy

white 94

as a follow-up, my wife typed the original post in for me so i could get some input asap. now, i come home and read it and it makes no sense. what actually is happening is as follows:

the car boosts normally (up to 10-11 psi) on the primary turbo, up to about 4500 rpms. at that point, it switches over to the secondary turbo and the boost immediately drops to between 6 & 7 psi, and slowly decreases.

it seems to me that the secondary turbo is not making any boost. i disconnected the ecu from the turbos and the result shows that there is no boost leak. can someone point me to a specific check valve or other part that would be one of the more likely items to cause this problem?

any help is appreciates as i haven't driven the car regularly in almost 3 months.

thanks,

andy

OK, if you replaced the hoses down to the actual turbo actuators (you have do these from under the car), there are small brass beads inside the hose that restrict airflow. There are no markings, but if you have old hoses you will see a slight buldge and can cut them and take them out and insert them in the new hoses. keep the hole aligned to allow flow. (I learned this the hardway)

sound like the same problem I was having with my old car before I went non seq well it ended up being the coupler on top of the y pipe check it good. The first time I looked at it I could not see a leak when I took it off is when I found it

Andy, it could be alot of things. I say try looking at the charge control valve , the charge control actuator, or the connecting hoses (even the large one)

That would be the first place for the boost to be getting lost.



Hope that gets you in the right direction.

Also it may be worth checking to make sure that the charge control and charge relief actuators are functioning properly.



Refer to the link for reference.....http://www.fd3boost.com/Images_page.htm

ok--here's what is happening exactly after extensive road testing. I will be checking all the lines/hoses tomorrow to be sure they are not the problem. i still have the previously described secondary boost problem. now, i'm out on the highway in third, below 4500, accelerate past 4500, watch the boost drop and shift quickly into 4th. rpms now around 3300 and should be primary turbo only. pedal to the floor and 3-4 psi of boost for about 2-3 seconds, then boost pops back up to 10-11 psi again until 4500 where the original problem kicks in. also, after longer periods of decelleration, foot off the pedal (high vacuum), i put the pedal to the floor below 4500 and again, only 4-5 psi of boost.

tomorrow i will re-hose everything fd3boost suggested and will check the results. if anyone has any input before then, i would appreciate the help.

andy

I'm having same problem. Today i have in plan to change TCA and TCA solenoids. I changed CRV, all the Check valves and did vaccum hose job. So i'll see if this fixes it. If not, i have no idea what else to do.

I'll let you know though.

FYI, the secondary turbo comes on line roght at 4500rpm.

So you basically not getting any 2ndary turbo.



i would check the lines I suggested first.

Then maybe start looking at the actuating rods and make sure that none of them are sticking.

Well i changed TCA, TCA solenoid, Checked charge control acuator (it works), changed couple of check valves, checked CRV ( works) i already have done sillicone hoses thing, and i still get 10-8-8 in all gears. I used to get 10-5-5 in first and second gear, but now i got 10-8-8 in all gears. Do you guys have any suggestions on what else can I do?



I got dp, catback, intake, pfs ecu, pfs ic and reliability mods.



Thanks