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chirs_87

By chirs_87,
in Engines & Forced Induction

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chirs_87 Rookie

chirs_87

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Posted (edited)

hay everyonehow r u all. ive got a question about my r32 gtst skyline. the boost guage in the dash only works in quarter scale deflection. so on idle it tells me im on 3.5 pound boost. and goes up from there. does anyone no what it might be and if and how its fixable. also does anyne no if they are electronic or vacume gauges thanks

Edited by chirs_87
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RANDY Veteran

RANDY

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Umm... you're definitely reading it correctly?

-7 then 0 then +7?

So a quarter way up the guage is actually vacuum between 0 and -7 mmHg.

In any case, there is a vacuum pipe running from the back of the plenum somewhere, up to the drivers side where you will find a little black box. That's the boost sensor, which then goes electronically to the guage... I thought it went to the ECU first, but someone said that this was not the case.

Edited by RANDY
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RANDY Veteran

RANDY

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It's rated in mmHg, not bar... bear in mind =-]

So you're seeing above zero at idle? I'd probably guess it could be a sticky needle in on the dash, or something wrong with the vacuum line or sensor.

Check both under the bonnet. I've described where and what it looks like, so just check that everything looks right. If you search, you might find the voltages that the sensor puts out or something, that you could then test with a multimeter.

I guess if it's on -7 when off, and then it goes to around +3 when you start the car, it can hardly be a sticky needle. Perhaps the electrical wiring from the sensor is being grounded on the chassis somewhere causing a misreading?

Not totally sure how the pressure sensor reads and reports the pressure, but if you have a poke around i'm sure you could narrow it down.

On idle it should be a quarter from the bottom (-7)... about -3.5mmHg.

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