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Problems with boost gauge HELP!

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Old 05-26-2010, 06:26 PM
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Default Problems with boost gauge HELP!

I can not get my boost gauge to work, its an autometer 3404. the gauge is plumbed into the back of my intake elbowwith a brass fitting. if i crank the car up i have vaccum on the hose going to the gauge at idle, and if i blow into the back of the gauge it reeds boost. i cant think of another reason it wouldnt be reading any ideas? heres the gauge i have:

Old 05-26-2010, 06:31 PM
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Um... boosted cars pull vacuum at idle. It isn't until you are actually driving the car that you will see boost.
Old 05-26-2010, 06:38 PM
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Lol..
Old 05-26-2010, 07:38 PM
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Originally Posted by MadIceV8
Um... boosted cars pull vacuum at idle. It isn't until you are actually driving the car that you will see boost.

im not that stupid, lol, im saying if it pulls vaccum at idle it should obvioussly read boost under a load, ive foot braked the car under load and put it on the trans brake and it still doesnt read when a load is applied, nor when im going down the track
Old 05-26-2010, 08:00 PM
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Is the hose getting kinked anywhere?
Old 05-26-2010, 09:20 PM
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If you tighten down the compression fitting to much it can kink it closed?
Old 05-26-2010, 11:10 PM
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Did you hook it off of the vacuum hose that normally went to the air pump? As that hose has a little check valve in it that will prevent boost reading.
Old 05-27-2010, 12:13 AM
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Originally Posted by MadIceV8
Did you hook it off of the vacuum hose that normally went to the air pump? As that hose has a little check valve in it that will prevent boost reading.
no, i have a single plane intake with eldebrock elbow, the back has a 90* brass fitting in it to go to the gauge, i dont think the hose is getting kinked due to it having plenty of vaccum on it at idle. i have the FPR referenced on the other side of the elbow the same way and it reads boost fine.
Old 05-27-2010, 01:21 AM
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Maybe you can disconnect the brass fitting at the manifold and carefully blow air into the line to test it with an air compressor blow tip. I'd shut off the compressor and let most of the air out first to make sure you don't put too much air into the guage.

If the turbo is making boost and the car pulls hard, isolate the guage and test it.
Old 05-27-2010, 05:22 PM
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Is there a kink going through the firewall or once it gets into the cab?
Old 05-27-2010, 08:37 PM
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is the turbo maybe too small to be able to feed the engine with boost and the gauge at the same time?
Old 05-27-2010, 08:50 PM
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I'm having the exact same problem with an autometer Z series boost gauge...shows vaccuum readings but even when the car is clearly into boost it doesn't register. I have mine referenced to the intake mani behind the throttle body.
Old 05-27-2010, 09:16 PM
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Originally Posted by BADBOB
is the turbo maybe too small to be able to feed the engine with boost and the gauge at the same time?
what? lol
Old 05-27-2010, 09:50 PM
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Originally Posted by lifeisgood
what? lol
see what happens is when the turbo is too small it can only feed the engine and isnt strong enough to push the boost through the small boost gauge line that far from the engine. Common issue for small turbo cars.
Old 05-27-2010, 10:26 PM
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Originally Posted by badbob
see what happens is when the turbo is too small it can only feed the engine and isnt strong enough to push the boost through the small boost gauge line that far from the engine. Common issue for small turbo cars.
lmfao!!!!!
Old 05-27-2010, 10:56 PM
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Originally Posted by OUTLAWZ RACING
lmfao!!!!!
x2
Old 05-27-2010, 11:38 PM
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Originally Posted by BADBOB
see what happens is when the turbo is too small it can only feed the engine and isnt strong enough to push the boost through the small boost gauge line that far from the engine. Common issue for small turbo cars.
thanks rob, now finish my downpipe.....

back on topic...any other ideas
Old 05-28-2010, 01:59 AM
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How much of the small tube are you actually using before you tee it down?
Old 05-28-2010, 02:15 AM
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Originally Posted by BADBOB
is the turbo maybe too small to be able to feed the engine with boost and the gauge at the same time?
Whoa! Alrighty then. I guess you do learn something new everyday .

Try referencing it before the TB and see what it reads. Curious myself. Boost leak possibly?
Old 05-28-2010, 02:50 AM
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Originally Posted by black98ws6ta
x2
x3, hahah


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