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Discussion Starter · #1 ·
Ok, first one, I'm pretty sure this is a bleed valve, but what I'm wanting to know is coolant or fuel. The brass makes it hard to determine the color of the fluid that is seeping out of it, and my sense of smell sucks.

Heres one a little further back for a reference point.


K, the next one is a sensor that says "pressure sensor". It's in the air to air manifold about 7 inches from the turbo. Is this a boost sensor? if so, why didn't gm just go ahead and install a boos guage on the dash?


Some identification on these wouldn't necessarily be helpful, but would be appreciated to keep me from pulling what hair I have out.
 

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First one is the schraeder valve and is fuel. It is between the filter head and the injection pump and reads vacuum when the engine is running (if you don't have an added lift pump). It should have a large black plastic cap screwed onto it to keep it clean.

Second is your MAP sensor (Manifold air pressure) and is a boost pressure sensor. It feeds back to the ECM in absolute pressure and is compared to the Baro sensor to calculate boost. There is a boost pressure reading on the CAN bus, but not tied to any gauges, can be read and displayed on aftermarket devices (Edge, EFILive Scantool, etc.)
 

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Discussion Starter · #3 ·
THANKS.... there is a black cap on it, but I had it off when I was looking at it and for the picture. So should the schrader valve be wet under the cap? How does it read vacuum? Or do you mean with a guage set?
What's a CAN bus?
 

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It's just like a big tire valve with the center spring loaded and it's used to read filter restriction with a vacuum gauge. It shouldn't be wet, and if it's leaking fuel that could only occur after shutdown and that means that it will suck air when the engine is running.

CAN bus is the main data bus used by the engine computers and controls to exchange data. There are many aftermarket devices that splice into the control harness and indicate parameters off the bus like gauges (Edge with Attitude display) or plug into the ODBII (OnBoard Diagnostic Bus II) diagnostic connector on the bottom left of the dash and will display parameters (EFI Live Scantool).
 

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Discussion Starter · #5 ·
Thanks for the quick reply
 
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