I think the Turbo Wastegate is frozen in the Open position. I am soliciting advice on 1) Diagnosing the wastegate, and 2) Repairing, not replacing. The truck is a 1990 Ford F350 2WD, 7.3l IDI, with ATI/Garrett aftermarket turbo.
I think I can replace the housing which has the wastegate, but I would prefer to repair the wastegate rather than spend $$ on a new housing.
Thanks. John.

 

Not sure what ATI turbo is but did you try taking the rod off and physically moving it with your hand? Pretty simple setup and should move freely, If you are talking about the "flapper". Or are you talking about the peice with the valve and hose going into it?

If you could just be a little bit more clear then I think we can help ya out

 

ATI is the company that packaged the Garrett Turbochargers most used by Ford dealers. Banks is a later manufacturer, all according to what I've found out online.
The wastegate is controlled by a pressure line from the pressurized intake manifold to a vacuum type (obviously not vacuum, rather pressure) pot, with a rod going to a flapper type valve. The valve moves a flap to open a channel diverting the pressure from the intake manifold. That flap will not move. I have no pressure other than ambient atmospheric pressure in the intake manifold, of course with lower pressure on acceleration due to the engine sucking air. So, wastegate open. Since it doesn't move, and there is no pressure, I conclude the wastegate is frozen open. I'm going to unship the turbo and have a good look. I am trying to find out the nuts and bolts, and solvents and lube and techniques, for getting the wastegate operating. The turbine spool spins just fine.

 

I believe you are thinking of ATS. When you get it off, squirt some brake clean/ wd40 around the rod that goes through the turbine housing. Soot probably just built up and caused it to freeze up. If that doesnt jar it loose then start with light taps from a hammer. Dont worry you wont break it