Whistling sound inside Cabin

[firstq]

My 92Q with 106K has been making a slight whistling sound (at times sounds like girgling sound - high pitched). The sound is audible inside the main cabin (while on the highway) and only happens around 65+ MPH and only when the gas pedal is pressed [when the foot is off the pedal, the noise stops].

Anyone else experienced this, any pointers?

Thanks

[diamondj30]

fuel pump maybe.

[diamondj30]

fuel pump maybe.?

[firstq]

Well - the sound clearly seems to be coming from the front of the car [direction wise]. I can hear it from the front.

I am thinking some leak is there [knowing that I did th plenum job myself].

Thanks

[DAEDALUS]

Sounds like a vacuum leak. Did you replace all the rubber donuts under the plenum? Spray carb cleaner around the intake and plenum and listen for the RPMs to rise while watching the mist. Maybe it's there at idle too...just can't be heard.

[firstq]

Prior to me getting the car, the dealer had cahnged all the 8 injectros - the plenum rubber rings appeared in good shape (soft and no cuts, etc) - so I dit not change em.

The noise is only heard at a specific speed - right around 65+ when pressing the gas pedal - and I can notice it everytime the car is at the speed

I have not tried the spary thing yet - may be I will shortly. Also, I still have the same old problem - if I disconnect the AAC - no noticeable drop in the RPM occurs - somewhere something is wrong. The AAC is crystal clean, and shows correct resistance.

Thanks

[Q45tech]

" the plenum rubber rings appeared in good shape (soft and no cuts, etc) - so I dit not change em."

APPEARED -----are you an expert on rubber rings?We change them every time the plenum is pulled unless they are less than 12 months old.

It the IAC [AAC] set 2.5-3 turns out from bottom [normal amount of bypass bleed air flow].

What is warm idle vacuum [18"].....with a digital vacuum sensor and scope you can look at all vacuum pulses in plenum [when synced to #1 plug firing pulse...offset 360 degrees].........you see a vacuum dip every 90 degrees as each cylinder sucks [opens allowing air pressure to fill] its charge in same with MAF voltage.On a meter things seems steady due to averaging on a scope you see all the individual shapes.

-v-v-v-v---v-v-v.