How do I fix TB Whistle...

[1Slow90coupe]

I recently installed a PP 75MM TB and EGR Spacer along with a C&L 76MM MAF and power pipe. I have not had much time to mess with the car until today. I also have a LC-1 Wideband AFR monitor hooked up.

When I start the car is idles very rough which I believe to be due to the TPS and Idle screw needing to be adjusted. It idles around 1200RPM and the AFR stays between 14.2 and 15.1 for a couple minutes then it tries to shut off. The AFR jumps to 20.00 or so and it dies. The whole time it has this extremely loud whistle coming from the IAC. I did some searching, and found that the PP and BBK throttle bodies are bad for this. Is there a way to fix it? What is up the the spike in AFR? I am off to work so I will check the thread as I can. Post up some advice please. Thanks for the help. Sorry for the :Word:

 

[gerzen]

its sound to me like you are running to lean because a vacum leak, try to spray at the TB and EGR spacer carbuklean at the union, whit the engine running at idle and if when you spray it at the gaskets of the two elements i mean where the TB met the EGR spacer and where the EGR spacer met the Intake, if the idle speed raise for a few second and then lower you have a leak on thoses gaskets, i have the same failure when i do the TB swap

 

[Biggeley]

The whole time it has this extremely loud whistle coming from the IAC. I did some searching, and found that the PP and BBK throttle bodies are bad for this. Is there a way to fix it?

I drilled a hole into the throttle body plate in the same size and location as the the stock throttle body. This seemed to lessen the whistling sound significantly.

 

[Daggar]

When I start the car is idles very rough which I believe to be due to the TPS and Idle screw needing to be adjusted. It idles around 1200RPM and the AFR stays between 14.2 and 15.1 for a couple minutes then it tries to shut off. The AFR jumps to 20.00 or so and it dies.

This sounds to me like either a vac leak (as mentioned above) or an intermittent or no contact condtion with the mass air sensor. Pull codes to rule out trouble with the sensor.

If I'm right about the sensor then it would account for your AFR spike. When you first start the car, the computer runs from a preset fuel table. Once the time runs out, it reverts to the MAF tables. If there's no MAF then it will default to "limp mode".

 

[1Slow90coupe]

Thanks for the info. I will check for the Vac leak and see if maybe the TB is not seated well. What would happen if I ported out the IAC holes some. By this I mean so that it is not a straight 90 deg turn...more like a 45????

 

[EMW150]

Thanks for the info. I will check for the Vac leak and see if maybe the TB is not seated well. What would happen if I ported out the IAC holes some. By this I mean so that it is not a straight 90 deg turn...more like a 45????

Good luck. I tried everything with the PP 70MM I put on our '87. Drilled the hole in the throttle plate like the stock one. Smoothed out the IAC ports,etc. Still whistles. Not as bad and it runs good but it still whistles at part throttle. I'm gonna scrap it and get an Accufab.

 

[1Slow90coupe]

Does the Accufab NOT whistle?

 

[iLkYsPoNy]

The whistle isn't hurting anything. It doesn't put a damper on performance or anything like that. Why waste money on another aftermarket t-body that may very well do the same thing? Unless you got money to burn or you're just that sick of the whistle... leave it be.

 

[302RollinHard]

Make sure everything is lining up. Whistles come from edges (TB to egr spacer misalignment) IAC port edges can also be sharp causing this whistle. Take a file or something of the sort and round over the edges of the IAC ports inside the TB and see if that works for you.

 

[PoopDawg]

My Edlebrock/BBK throttle body whistles too. Doesn't really bother me.

 

[fox-gt]

My Edlebrock/BBK throttle body whistles too. Doesn't really bother me.

same here.

 

[393 notch]

My accufab 75mm t/b whistles too... doesn't bother me. still works great and looks terrific.(polished)

 

[EMW150]

I fixed mine. It wasn't the throttle body causing it. It was a vacuum leak between the upper and lower intake. Sprayed carb cleaner around and it picked up like crazy so I pulled it apart and resealed it and now it's quiet as a mouse.

 

[Foxfan88]

i dont see how so many people complain about the TB whistle.

my PP tb whistled bad when i was N/A and i liked how it sounded.
just hearing the air rush in, something different.

 

[EMW150]

i dont see how so many people complain about the TB whistle.

my PP tb whistled bad when i was N/A and i liked how it sounded.
just hearing the air rush in, something different.

Mine was a very unpleasant whistle. Mine sounded EXACTLY like this. http://www.youtube.com/watch?v=50jX4_D8OpA Wait for the high pitched part.

 

[mustangfan1990]

I have the eldebrock/BBK TB and it whistled loud before I SC and everyone thought I was SC so I thought that was kinda cool. Now that I am supercharged I dont hear it at all