Noisy Vacuum Gauge

[Orixy]

Guys, I just got myself a new Pro-Gauge 60mm vacuum gauge.

 

DIYed it myself as I had installed one before one my previous ride. Similar to how my friend's setup, I had T-joined the vacuum hose leading from stock fuel regulator into intake manifold.

 

After installation, took car out for a run and realised that the gauge will produce a rapid 'tick tick tick' sound when I step on accelerator in high gear but low rpm (eg. 4th gear at 2000rpm). But no such sound when I rev the car during stationary or in high rpm. Idling is also normal at 17 Inch/Hg.

 

Thought my new gauge is damage so managed to get myself another vacuum gauge (AutoMeter brand) to test - same ticking sound...

 

Any idea what may have gone wrong?

[Yeobh]

Try to relocate nrearer to intake manifold mounting.

[Orixy]

Tks for replying!

 

When you said "relocate nearer to intake manifold", you meant my rubber hose running from the vacuum gauge to the t-joint is too long and I shld make it shorter?

 

Currently my setup is as in the attachment. Need your advise, pls.

Edited August 28, 2006 by Orixy

[Yeobh]

Yes reducing hose length and diameter does help and instead of doing a T distribution , try to tap directly from the manifold

Edited August 28, 2006 by Yeobh

[Orixy]

Ok tks! will try shorter hose & smaller diameter. Not so sure abt tapping the intake though...

[Orixy]

I managed to exchange for a new swoosh vacumm gauge. Hook it up using same length hose and same t-joint, the ticking sound is gone! Seems like both the pro-gauge and autometer are faulty... But now have new problem...

 

The reading with this new gauge at idle (aircon OFF) is steady at 25in/Hg... when I throttle suddenly, will drop to 2 then climb back immediately to 25. I then tried to pinch the rubber hose to starve it of air but instead of dropping to 0, the needle remain at 25?? I thought normal reading is 17-22? Hmm... maybe new gauge also faulty? Sigh...

[Elfenstar]

you pinch the hose and the vacuum level between the pinch and gauge will remain the same mah coz theres still less air. try pinching the hose when the car is off and then turn it on while still pinching the hose. it shouldnt move from 0.

[Orixy]

Silly me! I didnt realise that the air shld still be in vacuum form when I pinch durin engine on.

 

But when I had my old vacuum gauges, when I pinch it will drop to 0 leh... funny

 

Anyway, reading of 24-25 at idle isit normal? I had my TB slightly bored but butterfly remains, does this affect the reading?

 

Tks!

[Elfenstar]

it would affect it, but the exact vacuum depends car to to car. 20ish is about right on idle.

[Orixy]

Ok tks.

[Yeobh]

There is a minute leak , when you pinch the hose , atmospheric pressure rushes in and caused the gauge needel to swing to zero reading.

Vacuum reading @ 25 inch of mecury is the highest any veturic can creat.

[Orixy]

"There is a minute leak , when you pinch the hose , atmospheric pressure rushes in and caused the gauge needel to swing to zero reading."

>> you mean it should drop to zero if I pinch it properly and starving air totally? Cos mine doesnt... here's how mine works: pinch hard, needle remains at 25 wont move -> still maintaining pinch and rev, needle still wont move -> if I let go of my pinch as I continue revving, needle will move again according to revs...

 

 

"Vacuum reading @ 25 inch of mecury is the highest any veturic can creat."

 

>> think you meant venturi instead of veturic? Does my highish 25in/Hg reading mean anything to my engine?

 

Tks again!

[Elfenstar]

no he means it shouldnt drop to zero. if it does then theres a leak.

[Orixy]

I see! Tks for clarifying. That means my new gauge is ok...

Edited September 5, 2006 by Orixy