My brother has a 87 rx7 TII and when he gets on it alittle it started to spitter and backfire and i see the boost go to about half then drop dead he put a fuel defender on it and no change it smokes alot and he not sure what to do. he also put a new fuel pump becasue he has more the 10psi running in it and wasnt sure he was getting enough boost .someone told us it might be leaking oil into the turbo since it burn alot of oil is thats whats causeing a problem any advice would be apreciated.

 

If he's running a lot more than 10psi on the stock turbo and IC, he could have blown his turbo. Don't take my word for it though, theres people who can answer your question much more specifically than I can.

-Andrew
90 TII

 

check your oxigen sensor.

 

Oxygen sensor has nothing to do with it.

Vacuum leaks are a great place to start, as well as the TPS. But if the turbo is bypassing a lot of oil, fix that as well.