no boost from 1st turbo but 2nd turbo is working fine ??
 

hey guys
i'm having a problem i'm not having any boost from the 1st turbo but 2nd turbo seems to work just fine pulling from 4500rpm and above (i still have the sequential system)
i've install a new rad a blitz fmic and replace all the vaccum hose for some new ones and ported the wastegate and also a avc-r ... anyone have similiar problem ?
before i had those parts in the car i had no problems with the turbos
what could it be ?
it's driving me crazy...

pull your intake duct and check the primary turbo, it is easy to access since it is the forward turbo. if the shaft is siezed, blades worn or broken or if it has excessive shaft play then you need to have it rebuilt. if it appears ok then you may just have a massive boost leak somewhere in the intake system that you will need to trace out, likely place would be the couple that comes right off the charge pipe to the plastic elbow to the intercooler, that coupler likes to split wide open with years of age and abuse.

Not likely a boost leak if the 2nd turbo works fine. I would start by replacing the check valves. They are frequent culprits in your situation

actually i've boost but it's only 0.20bar tops and the avc-r is set to 0.85bar :(

I would start by looking for brittle, loose, or leaking vacuum lines. Especially the ones for the charge control and turbo control actuators.

Dave

I had a very similar boost problem after I had my seq. simplification mod. I will have no boost on primary turboes, then after 4500 rpm, both comes on like they are wired together. I pulled my UIM off after countless hour of troubleshooting ( should have done it in the first place) It was a broken nipple off one of the 4 functional solenoids, and the vac. line was disconnected. Could be the charge control solenoids ( if I remember correctly) The primary turbo came back alive like a dream and been solid since. I put my money on a vac. leak.

just had this issue on my car. culprit was an actuator rod that fell off the precontrol door. look under your passenger side of the car and you will see the actuator (one with longer rod is the precontrol), make sure its connected. there is an e-clip that holds it on.

mike

I went through this same problem on a car I bought with a turbo issue last year. I would pull the UIM off and double check all your hoses with the diagram. I would check your Charge Control Acuator solenoid by putting a 12v source to it and seeing if it clicks. Another test is either blowing air or sucking air through it and seeing if it clicks(don't remember which off the top of my head). If it clicks(on both 12v and pressure test), the solenoid should be good. Underneath the car, you should check the Turbo Control Acuator and ensure that the gate is not stuck open.


BTW, the website that Red94Rx7 listed is great!!!