Could you guys please help me. I have a 93 sc300 with the Toyomoto kit and for the longest time my car has been well behaved. I drove it this morning though and I noticed that my boost, which is set at 12 psi max on low mode is now spiking all the way to 21. In fact, even when I switch off the boost controller, my boost still climbs to 21. My previous max setting was 14 psi on high mode. Can any of you guys give me an idea of what to check. I don't want to drive the car in the meantime because i'd hate to risk frying my rings or worse. Thanks in advance.

By the way, can you guys also tell me how to keep my check engine light from lighting on occasion when I engage boost from low cruising rpm. The error code points to the Air Mass sensor getting an off chart reading so it lights up. I'm just wondering if there's a way to keep this from happening.

 

what is the rating on your wastegate spring?

 

I don't know the rating because the turbo unit has an internal wastegate.

 

i dont know how the internal wastegate works, are there any loose vacuum lines? on an external wastegate you need to connect a vaccuum line from the turbo to the wg.

 

I don't think there are any vacuum lines disconnected but i'll check. Thanks

 

It sounds to me like the vacuum line that goes to the wastegate actuator came loose or cracked or got a hole in it somehow.