Waste gate set up?

[phicho]

1984 hot air. The waste gate lever when disconnected has a travel of approx 90 degrees. However the when conneted the vacum actuator, I can only get the vacum actuator to move the gate only about 45 degrees. How much should the wast gate open?

How far should the vacum actuator move the waste gate lever?

I connected the vacum test tool to the drivers side port of the actuator and it will pull about 25 inches and hold. When connected to the passenger side port it will only pull about 20 inches and bleeds off slowly. I am wondering if the waste gate vacum actuator is bad?

The engine will only pull about 8 to 9 inches of boost. I live in Colo at about 5000 ft of altitude.

 

[BRAD_PADGETT]

1984 hot air. The waste gate lever when disconnected has a travel of approx 90 degrees. However the when conneted the vacum actuator, I can only get the vacum actuator to move the gate only about 45 degrees. How much should the wast gate open?

How far should the vacum actuator move the waste gate lever?

I connected the vacum test tool to the drivers side port of the actuator and it will pull about 25 inches and hold. When connected to the passenger side port it will only pull about 20 inches and bleeds off slowly. I am wondering if the waste gate vacum actuator is bad?

The engine will only pull about 8 to 9 inches of boost. I live in Colo at about 5000 ft of altitude.

I have not tested an actuator with a vacuum gauge. I suspect that you have a non-adjustable(stock) waste gate actuator rod and the actuator is operating normally. Altitude will not have an effect. Does the actuator rod have threads and a nut? Brad

 

[phicho]

The rod is not threded, does not have adjustment nut.

 

[BRAD_PADGETT]

Everything should be fine. Stock boost is around 10 and your boost gauge in the dash is inaccurate. Tach is inaccurate as well. All Buick in dash boost and tach gauges fail. I would not recommend installing an adjustable waste gate acutuator rod until you have a knock gauge. Leave it alone and enjoy. Brad

 

[phicho]

Thanks Brad.

Where can I find information on how the waste gate works, opens closes, vacuum etc? Since vacum is dumped when the throttle is opened, is the waste gate vacuum servo spring loaded to the open position and then vacuum pulls it closed until the throttle is opened and the vacuum is dumped?.

 

[LOT]

wastegate

Not positive but I believe the waste gate works something like this. It has 2 ports --inside the unit is a diaghpram with 1 port on each side of diaghpram and 1 spring. The spring holds or pushes the rod in the closed position. Boost on the other side of diaphram will overcome the spring to open wastegate. I read somewhere that the other port is for vacumn so when climbing a hill the vacumn will open WG. Been A good while since I looked @ an 84-85 stock setup. I capped vacumn ports @ both ends on mine. 87 does not have the other port.