Stock Boost Gauge not working!!!

[Boostin 7M]

Hi guys, I have a '90 turbo 5spd w/ an apexi n1 exhaust and hks air filter with recent spark plug and wire change. Just yesterday I was driving and started boosting (gauge pinned at 8psi) when the boost gauge needle suddenly dropped to 0 while the car was still in boost and stayed there!
So as of now when the car is off, the reading on the gauge is -4 vac. When the ignition is turned on, the gauge shoots up to 0 after a second and stays there even with the car turned on (even during idle, normal driving and boosting). The car boost normally even after the gauge malfunction.
Can anyone please help me shine some light on this problem, I tried searching the forum and other sites and couldn't find anything. Any help will be highly appreciated. Thanks in advance.

 

[JustinGotA1j]

When that happened to me on my 1JZ it was just because a vacuum line had popped off.

 

[RazoE]

good riddance..

replace it with a more accurate aftermarket gauge hooked up directly to a vacuum line, and replace the OEM boost gauge with an NA voltmeter...

 

[rayall01]

You blew of a vacuum hose most likely. Happened to me when I purchased a cheap set of silicone hoses, had to use small wire ties to hold them on.

 

[Boostin 7M]

I just would like to thank you guys for replying.
Where is this vacuum hose located in the engine bay? Thanks again.

 

[grimreaper]

pop the hood and look around, not complicated and there shouldnt be ANY loose ones laying around. Start at the back of the intake mani and work your way through them

 

[Boostin 7M]

Problem is finally fixed! Found a tiny vacuum hose right behind the end of the manifold dangling. Pushed it back in and boost gauge is working again!!! Thanks for all the help guys.

 

[rayall01]

Problem is finally fixed! Found a tiny vacuum hose right behind the end of the manifold dangling. Pushed it back in and boost gauge is working again!!! Thanks for all the help guys.

Now get a small zip tie and put it around the hose where it blew off, or replace the hose with a new one, because it will probably blow off again.

 

[Boostin 7M]

Now get a small zip tie and put it around the hose where it blew off, or replace the hose with a new one, because it will probably blow off again.

Yea, I think I'll do that to avoid this from happening again. But as mentioned by razoe, I'm going to look into getting an aftermarket mechanical gauge in the near future.

 

[92TealSupra]

Happened to me as well. I am sure a number of us on here have had this happen. having a aftermarket gauge will let you read your boost a lot better. I am going to keep the stock gauge in my car. I like to have a clean MKIII and keep it as stock as possible. It's nice to have everything the factory had there for a long as possible!

 

[alloyguitar]

I, personally, also replaced my boost gauge with the n/a voltmeter and moved my boost gauge to a pillar pod. That way you keep a stock look if you want to convert back (for whatever reason) and you can take advantage of a much more accurate measurement.

 

[Poodles]

The stock guage IS accurate, it's just dampened (easy to remove and make it as fast as any other electronic boost guage, and you can also change the scale of it so it shows more boost)

 

[alloyguitar]

It may be accurate, but even dampened I find it annoying that it doesn't show much vacuum, and if it's modified you're guessing what it's reading.

 

[Poodles]

Not guessing, make a new face...

Lemme find the post...

EDIT: found here http://www.supramania.com/forums/showthread.php?t=64342&highlight=boost+gauge

 

[alloyguitar]

Wow, that's pretty crazy. I hadn't ran across that before. The calibration was what I was really wondering about, since it's a potentiometer. That's a pretty neat idea.

 

[Boostin 7M]

That's a great idea for a boost gauge! Thanks for the post poodles.

 

[rayall01]

Yea, I think I'll do that to avoid this from happening again. But as mentioned by razoe, I'm going to look into getting an aftermarket mechanical gauge in the near future.

Well just be sure you have tight vacuum hoes, cause if any blow off, you won't get any reading with a mechanical gauge either.