Stock Boost Gauge Problem

[LuPix_S15]

Hi folks :wave:

My stock boost gauge (on the A-pillar) has been working a treat until recently

There's still power to the gauge cos the amber light always comes on ok at night etc. However, I've noticed that the needle will sometimes drop to -7 on the gauge and no amount of revving or driving will make the needle move again?!

Funny thing is that usually when I first turn on the car, it will work ok and starts fine. Then as you drive down the road for 10 mins and then look at the boost gauge, it's gone to -7 and not moving.

I've had a look at what I believe to be where the sensor for the stock boost gauge connects - in the engine bay, near the battery side where a clear vacuum tube runs to a connector with wires leading to elsewhere... think this is the sender/sensor for the boost?? All seems ok - tightly connected etc.

Anyone have any ideas???

Cheers,

James

 

[LuPix_S15]

Forgot to say, it's boosting fine - consistently hits 0.6 on full boost which is what I expect so don't think a leak is the problem here...

 

[Yakozan]

common problem with the stock gauge.
I've had it for years. Works sometimes and just sits at the bottom sometimes.

Don't really know what causes this and I'm not to bothered as I have another gauge to read boost. But I suspect it's either the wiring (maybe a bad earth) or the gauge itself. Could be a bad connection on the backside of the gauge which needs resoldering or maybe a condensor or something which needs to be replaced.

I'm not very good with electronics but maybe you can leave the gauge face to an electronics repair store and they can check it out?

It's a relatively common problem on RX7s on the rev counter. That's often a bad condensor which needs to be replaced and resoldered.

Not sure that solder is the right word in english. But it involves a pen-like device

 

[Dazz0i]

yea soldering is right.

swap out the stock piece of pipe going to the solenoid, sometimes this splits and leaks, giving a negative reading.

 

[Matt_S]

WHy is it that hose is red? All the Spec Rs Ive seen have red hose for the boost gauge sender, but no idea why :wack:

 

[Yakozan]

WHy is it that hose is red? All the Spec Rs Ive seen have red hose for the boost gauge sender, but no idea why :wack:

Stock hose is black.
It's probobly been changed. Can't say why you've only seen red ones though.

 

[gunner93]

The stock hose has a plastic tube ends which splits easily. Just have that replaced. Heard the stock boost gauge is not accurate?

 

[LuPix_S15]

Thanks for the advice as always :thumbs:


If I'm planning on fitting a Greddy Profec B as a boost controller soonish then can I used this for constant boost readings or is it too small to look at etc?

Dumbo question 2 - I've just bought a set of Defi Link Display plus Control Unit 2 and oil temp/pressure sensors. Gonna get these all fitted soon. If I'm planning to fit the Greddy boost controller, is there any point in getting a Defi boost sensor so I can use it on the Link Display unit?


Cheers

 

[StarletRick]

the defi boost sensor works with the defi boost gauge. if you have the boost gauge, you need the sensor.

the greddy profec is POO for monotoring boost. you can beat a good old needle.