Just bought a beautiful 1994 FD from out of state and picked it up today. Car has 30k miles on it and appeared to be in excellent shape for being 30 years old. The only mods that ive found are a Racing Beats intake duct, downpipe and Racing Beats catback. I filled it with gas, added .5oz to gallon premix and did a 2nd gear pull after it was warmed up. It went over 12 psi then steadily dropped to 5lbs. Below is a video, had to cut it short due to a bus. Ive searched the forum and had a few questions and would like some help diagnosing this. Here is my thought process. Their are two possibly related issues, higher than stock boost and the secondary turbo not kicking on.

Higher than stock boost issue:
I dont think the mods would cause an increase in boost by themselves. I could be wrong but i would think that making the car breath easier would not effect boost or would cause a decrease in boost. I took a look at the ECU and it appears to be stock. I took a look around the engine bay and couldnt find any boost controller. Are my assumptions wrong and would those mods increase boost? What would cause this?

Second issue is a continue drop in boost. I think that the secondary turbo isnt kicking on. Would appreciate some guidance on troubleshooting this.

 

so long as the stock cat is in place, boost creep is highly unlikely. what that boost pattern looks like is a non operational secondary. it could be a lot reasons for it and its not necessarily the turbo itself being bad. it could be as simple as the arm on one of the actuators is no longer attached, a non functional solenoid, a vacuum line not being attached somewhere.... the list is very long of possibilities. you kind of have to just get in there and inspect