Wierd boost problem!

[91BlackLaser]

I replaced the 14B on my son's 91 Laser with another 14B today. The spare 14B had very little shaft play and no in/out play. I installed it and took it for a boot and everything was fine. My son drove it for a while and all was fine but when he shut the car off and drove it again the turbo would not boost until about 5000rpms and it was making a loud sound kinda like a ghost going wooooooooooooooooo. It will not build any boost in low rpm range and then it hits about 5000rpms and hits 16psi in an instant. The car is is only seeing 5" of vacuum and before it was seeing 10". The car has HKS cams. Any ideas? I was thinking a vacuum leak.

 

[oldman]

Boost leak test.

 

[91BlackLaser]

I made a boost leak tester and did find a leak. The leaks I found are little rust holes on the outlet neck of the IC. I fixed that and the car now boosts without a problem. The noise is still there, though it is alot quieter. The problem I have now is that the car boosts at over 20psi all the time. I turned the boost controller all the way out and it still hits over 20PSI. Has the wastegate gone bad? Would it make that noise? I am going to try and run it off the wastegate and see what happens. Just posting to see if anyone else has had this problem.

 

[oldman]

1. Is boost shooting straight up to 20psi or does it hit a lower level then slowly creeps to 20 as rpm increase?

2. fixing one leak doesn't mean you're done with the leak test. How much pressure did your boost gauge tell you during the pressure test after you fix the leak at IC?

3. Do you have the Turbo XS Standard BC? How it it hooked up?

 

[91BlackLaser]

1. Is boost shooting straight up to 20psi or does it hit a lower level then slowly creeps to 20 as rpm increase?

2. fixing one leak doesn't mean you're done with the leak test. How much pressure did your boost gauge tell you during the pressure test after you fix the leak at IC?

3. Do you have the Turbo XS Standard BC? How it it hooked up?

I still have few small leaks but will tend to them this week. I swapped the wastegate actuator and the car now runs about 10psi. I will put the controller back in and see what happens.