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Discussion Starter · #1 ·
I am having problems with my 760 w/ a Garrett turbo.

At 55 on faily level road all is pretty smooth - turbo gauge stays put at about 1/4.

Push it a bit harder going around traffic or up a hill, and turbo kicks in - good punch - but then will drop out, just for sec, and then pick back up. At other times when you push it, it will speed up - like with extra boost - then back to normal boost.

Cruise at 70-75 with cruise on and turbo will engage erratically like someone who would pump the gas - then let off. Then it may go for a spell just as smooth as can be.

I hope someone has some ideas. I just spent over 500.00 at the shop. This was the one thing that he has not figured out yet.

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'89 764 (110K), '94 940T (180K) , '92 745T (totaled 2-10-05 RIP)
 

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Check the vaccum hose to the waste gate valve and check your induction hoses and make sure they are not collapsing under boost.
 

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QUOTE(Tech @ Feb 23 2005, 10:18 PM)Check the vaccum hose to the waste gate valve and check your induction hoses and make sure they are not collapsing under boost.
[snapback]3913[/snapback]​


I really am not sure where the waste gate valve is. Do you know of a picture ? ...or maybe just describe it.

Would I check the hoses for collapse by reving the motor with brakes on with someone watching the hose to see if it changed?

Thanks for the help.
 

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Yes carefully have some one step on the gas and get the car into boost and stand on the side of the car and watch the hoses and see if they collapse.
The waste gate valve is the gold peice on the turbo in the picture I attached.You can see a little peice of a vaccum hose still attached.
 

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QUOTE(Tech @ Feb 24 2005, 08:23 AM)Yes carefully have some one step on the gas and get the car into boost and stand on the side of the car and watch the hoses and see if they collapse.
The waste gate valve is the gold peice on the turbo in the picture I attached.You can see a little peice of a vaccum hose still attached.
[snapback]3933[/snapback]​


I will try that with the wife a bit later. Thanks.

I do not see the linkage shown in your pix. It may be that I am looking from above - and it is underneath. The is a short hose(about 6" long) running down to a device below the turbo. Is that hose running to the waste gate below the turbo?

While I was pondering at the car, I noted there is a silver colored device just above the water pump , in front of the #1 cyl. It looks like a large vacumn device. Out of the bottom of this is a good size hose (about 1 1/2 - 2" dia) that connects to the main intake from the airbox to the turbo. There is a single vacumn line that connects from the top of this to the intake manifold.

1. The curved hose from the device to the large intake is somewhat soft on the bottom of it's curve, and up the side a bit.
2. The vac hose has a small red device in the middle - with arrows on it indicating that the flow of air be toward the intake. I disconnected it from the device above the water pump, and blew through it - no resistence. I then took it off on both ends - took off one half of the hose (toward the turbo) and blew into the red device (stopping the other end). When I blow, I feel air coming back toward me. When I suck the air - the is a bit more resistence, but air still moves freely - I just don't feel it as when I blew.

Have I found something - I hope, I pray.
 

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That valve could be the problem if air moves both ways.The small elbow if it has a hole in it replace it if it is really soft see if it is collapsing.
 
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