Turbo not right... Help!!!

[dgallo]

I have a 1986 SVO with a stock motor. The only thing I have added is a K&N Air filter. I recently just replaced the vaccum lines coming off of the Boost Control Soleniod (I was only getting 10psi in Premium mode), this did correct the psi problem, however now the car is having major problems when the Boost goes past 10psi. Basically when you nail the gas the Turbo spools up, you hear the sweet whistling sound, the cars starts to pull real hard until about 10psi, then all of a sudden the turbo gague goes pegged at 17psi, the car looses most all of the turbo power and the turbo makes this strange noise like a screech, almost like you ran over a cat. If I stay in the gas, the gague and boost bounces back and forth between 12 & 17psi and the car bucks and kicks a bit. I think I can hear some kind of vaccum sound too. I have inspected all of the other vaccum hoses and they seem okay. I have checked the timing it is good. Like I said the car runs great when the premuim switch is off running 10psi, beyond 10psi, poo poo city. I am new the turbo scene and still learning about how turbos work, but I have heard alot of talk about waste gates. My guess is it has something to do with that. Should I put a manual boost adjuster in? Any help anyone can give would be greatly appreciated. I love this car and plan on keeping it a long time. Thanks for your help.

Dan

[SVOeric]

If you are hearing rushing air, you probably have a loose hose somewhere.. not vacume, but intercooler to turbo, or intercooler to throttle body, or possibly vam to turbo.

If one of the clamps is a bit loose, that will cause a lot of the problem you are having.

The other thing is, are you sure you got the hoses to the boost controler back on?

On a 86, the boost will peg if you have one of the boost controler hoses -- that's not usually good for the turbo, or other compenets involved..

 

[dgallo]

Turbo

Eric,

Thanks for the quick responce. As far as I can tell all of the hoses are connected. I will certainly double check all of my lines and hoses tonight. I do know for a fact that the hoses from the BCS are connected properly, I did double check that yesterday. What is the VAM? I know thats a dumb question. For arguments sake, lets say all of my hoses and intercooler connections are good, what might be the problem after that? I'm trying to cover all of my bases and learn as much as I can about the SVO and turbos.

Dan

[SVOeric]

the VAM  is the Vane Air Meter.  It has the air filter on top of it.  It has a hose connecting it to the inlet on the turbo.

The other thing to check it that hose between the turbo and VAM, there should be a spring like round metal thing inside that hose that will keep it from collapsing under pressure.  If that spring is gone, or pushed all the way to one end, that would certainly cause the boost to drop to nothing.

I dont think the wastegate has anything to do with this issue.. it sounds like it is opening fine.

past that... I would check the normal tune-up items...

If you are hearing rushing air when youget above 10 psi, I would almost bet on either a hole in one of those 3 hoses, or a loose clamp somewhere.

 

[dgallo]

Turbo

Eric,

Thanks for the advice, I will check all of those items that you have mentioned. I'll let you know how I make out.

Dan