Actuator stuck??

[CombatComProg]

My friend's stock '87 GN has only been getting about 8lbs of boost. Recently it dropped to 0-1lb of boost. The actuator arm looks heavily corroded as does the swing-arm. I grabbed a pair of pliers and had to use a hell of a lot of strength to wiggle the arm -should it take a lot? I jumped back in the car and got 3-4lbs of boost, an improvement from 0 but still nowhere close to 8lbs or the stock 13-14lbs. I removed the vacuum line to the actuator, jumped back in the car, went WOT and still never saw past 3lbs. Does this mean a bad actuator or stuck puck? How can I remedy a stuck puck if they even get stuck? Thanks!

 

[CombatComProg]

Anyone?

 

[turbo2nr]

Sounds like an ATR down pipe. They get stuck. If it got stuck closed, the motor may not live, overboost! Better find someone to help.

Or, is it a stock downpipe?

 

[rodman99999]

Disconnect the actuator from the wastegate arm, and move the arm back and forth. If you have full travel there: your wastegate is probably OK. If it were stuck shut: you'd be overboosting. Chances are: the actuator is stuck and holding the puck open a little, given it's corroded condition.

 

[turbo2nr]

The accuator is just a spring loaded can, with a rod attatched to the bottom of diaphram inside. Not really anything to get stuck in there. Look at where the rod exits the can, no friction there, usually felt or even nothing rubbing the rod, even if it is super corroded. You can blow air into the accuator to test for a blown diaphram. I guess the spring could also get weak, but never heard of an accuator getting frozen in one position (not yet at least)

If something were to get stuck, it would be the swingarm binding in the bushing in the DP, or stock elbow. Sometimes it moves freely when cold, then gets stuck when hot. If you have an ATR DP, then it most likely it the problem.

 

[CombatComProg]

Well, one time the vacuum line came off of my actuator on my car, and I imediately got dangerous boost levels since the actuator would never open the wastegate. I removed the vacuum line on my friend's actuator to see if a the same effect would happen, and it didn't. Low boost level remains the same. This leads me to believe the wastegate puck is stuck in one position. Anyone agree? How can I fix this?

 

[ANDYS87]

Remove the actuator rod from the lever for the puck. The lever that controls the puck should swing freely. If it doesn't swing freely, its probably seized. You'll have to disconnect the downpipe, and remove the turbo's exhaust housing. After its off, maybe you can free it up. If you cant...you might have to relace it. If thats fine, it might be the acutautor assembly. The diaphragm might be shot. Poston's sells an adjustable one for $84.88. Check out KirbanPerformance also.

 

[ANDYS87]

It sounds like his puck is stuck in the open position. Do what I just said.....remove the actuator's rod from the puck swing lever. If the puck lever moves with little effort, its good, so replace the actuator.

 

[turbo2nr]

Do you hear the turbo spooling up. You may have a leak before the throttle body, the turbo would be trying to pressurize the atmosphere

Or your puck is not covering the wastegate hole, but even then you should still get some boost, like eventually 12PSI?? or even higher.

Or you have a hole in your exhaust (headers) the size of an apple

 

[turbo2nr]

So what parts are we talking about here? Terry Houston Down pipe? Stock elbow? Stock accuator? ATR Down pipe? Different turbo? Any idea what it is, or if anybody ported the wastegate hole?