Low boost (1st turbo only) issue!!??

[ESPJohn]

Hello. I'm sure this problem has happened before, but I couldn't track down a thread on this.
I just got a '94 2JZGTE. On the second day the 2nd turbo went out, meaning it is not making boost. The gauge hits 8 psi and stops. I checked the VSVs and the one for the By-pass was bad, so I changed that but no improvement. I saw on another site where they wire the EGC Act. and the Intake Air Act open to run true twin turbo. They said you would get more lag, and they were correct. The boost now goes over 8; it hits about 11-12 and gets there slow. I triple checked the vacuum diagrams, but do not have an answer for the problem. So now I have 11-12 psi and now the engine shutters hard at WOT. Is this the fuel cut? If so what's the solution for that one as well? My first issue is why is the 2nd turbo not kicking on at 4500 like designed?

Thank you in advance.

 

[ESPJohn]

I installed a FCD from HKS. During the installation I found a few wires that the Previous owner messed with, twisted together, and taped. I installed the FCD and repaired the messed up wires. I also installed a second boost gauge, to check the one that came with the car (no name on it). The boost gauges in the car reads low (mine 15 psi / the car's 10 psi) and the signals are from the same source. BUT NOW there is a flutter at 7-8 psi. If I remove the hose to the wastegate (no Wastegate) I can carefully bring the boost up to higher boost levels, but the sputter still occurs at 7-8 psi. To make this more difficult, my scanner will not read when the engine is running, only KOEO. It's not the MODIS, I use it all the time.

Any ideas out there?

 

[ESPJohn]

I've gotten past the communication issue. I have interestingly found that the knock sensor is going off at 0 psi and the car starts sputtering at about 7-8 psi. And I believe that to be the culprit. I unplugged both knock sensors and still have the same symptoms and a knock reading on the scanner. Is there an issue with these cars that give a false knock reading???

Thank you

 

[Nick 95 6sp]

I've never had a false knock reading or heard of that being an issue. In your first post you asked if "shutters hard at WOT" is fuel cut and this is not fuel cut. When you hit fuel cut it feels like the engine suddenly shuts off or somebody stomped on your brakes.

Have you checked your plugs lately? It sounds like possible misfire. What plugs and what gap are you running?