Sinful7

I'm not getting boost from the secondary turbo. I start from a stop, run 14PSI (I have a PMS), at transition it drops to 8, then after tranision, 4 or 5 PSI, steady. I unplugged the PMS to see if that was the source, problem still exists. It accelrates like when the vacuum chamber hose pops off. Vacuum chamber hoses are connected. I haven't started pulling **** yet because I don't want to get in there and have no idea what I'm looking for.



Here's the twist: if I release the throttle (sometime after transition), and slam it back down, I instantly get 14 PSI out of the secondary.



Thoughts?



If you can, please try to list causes in addition to procedures.

FikseRxSeven

if you release the throttle and slam it back down again.... doesnt that start the sequential sequence all over again?



did you check any leaks?

Sinful7

I don't have any idea what releasing and slamming the throttle does. I have not checked for leaks - not sure where to start...

FikseRxSeven

do you hear any hissing sounds in your engine bay? or when you're at WOT? check couplers, and all the plastic piping.



i have a hole in my crossover pipe and i have the same symptoms as you... but on mine it boosts to 10, dropps to 5 then slowly boosts up to 10 again. i have a hole underneath my crossover pipe that i can fit a finger thgouh

Sinful7

no hissing, no leaks, no holes, near as I can tell. I just replaced all the OEM couplers, and I double checked them, they're tight. After transition, I won't get more than 4 PSI - the wastegate is being held open, I'm thinking. There's no other way I'd be losing 10PSI and not hearing it. I wonder if i have a little problem with the vacuum signal leading to the wastegate actuator, or the solenoid that controls it. Time to start pulling the UIM maybe?



Edit: I've sliced it down to two causes - the plumbing to control the wastegate and the wastegate itself, or the signal triggering the solenoid that controls the wastegate.