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Stock Turbo Boost Gage-'90

I'm not too sure about the stock boost sensor, but if it does have a vacuum line that runs to the gauge then that could have come undone from the gauge itself. I had this happen to me on my aftermarket boost gauge.

The gauge is electric. The sensor is located up behind the driver's side wheel well, right in front of the cruise control actuator... they share the same vac source.

Quote:

Originally Posted by Benesesso (Post 77908)

there has to be some vacuum line in there.

Nope, not from the factory anyway. It's possible you're hearing a massive boost leak through the firewall, or something electrical that's buzzing.

Quote:

Originally Posted by Benesesso (Post 77908)

Thanks, but this car seems to have gone nuts. There is a strong hissing noise from the boost gage area, so there has to be some vacuum line in there.

Quote:

Originally Posted by Benesesso (Post 77918)

Here's what's really strange. I plumbed a small vac. "T" fitting into one of the intake air chamber vac, lines, and ran it inside the car.

WTF? It's stupid shit like this that's why no one's ever going to be able to help you... did you just forget that YOU added a vac line where the NEVER WAS ONE? Jebus.....

Quote:

Originally Posted by Benesesso (Post 77918)

Here's what's really strange. I plumbed a small vac. "T" fitting into one of the intake air chamber vac, lines, and ran it inside the car. As long as my mech. boost gage is plugged in, I can easily hear the noise. But the second I unplug the gage, the noise stops.

Sounds like the diaphragm in the gauges shot. Put a bike pump on the reference port and see if it hold pressure.

There is NO stock vacuum line run past the firewall... none.

I said stupid shit because YOU posted and asked where the vac line was... I told you, then you argue that it has to be behind the dash because that's where the hissing is... THEN you admit to having put a vacuum line behind the dash yourself... And now you try and twist everything I said about the noise possibly coming from the stock gauge and you seemingly ignore the part about diagnosing your mechanical gauge (the diaphragm is in YOUR gauge, if it holds pressure, you test the hose next)?????

No worries though. I haven't the patience for this right now, so I'll step aside. Good luck with the problem.

It doesn’t sound like the turbo has gone down, as this started straight after you took it in for the starter motor replacement, I would more than likely suspect someone has connected something incorrectly or forgot to connect a hose up. Could be a split hose or a hose connected in the wrong place, or a hose not connected. The pic below shows where the stock gauge connects to the pressure sensor via an electrical connection. Aftermarket mechanical boost gauge could “ T ” in anywhere along the hose (yellow arrow) that connects to the sensor. Unrelated to your problem, but interesting all the same Link

http://i17.photobucket.com/albums/b5...reSensor-2.jpg