The Fun... low boost problem, whooshing sound...

[rjjuge]

Okay. Still pegged at 7psi, now I'm looking into the fact that maybe the chip is running properly. When I take my foot off the gas, I get a sound almost like a blow off valve, it's like a "whoosh" and kinda like a cat purring, but loud. Only when it's under load. It seems exactly like a blow off valve, but there's not one installed.... Any ideas?

Oh, and where is the heater connection? I need to know where to run the wire from the vacuum pump to...

Thanks... god this sucks.... Would the fact that an o2 sensor was not hooked up prevent the car from boosting at all? I unhooked it for kicks, and it still spikes at 7psi.

FInally, in a 95 s4, the bar. sensor is right next to the boost transducer, right? with the blue plug and an open vacuum nipple. THen the map sensor is to the rear of that little spot mounted to the side of the car?...

[rjjuge]

oh, before I installed the mech. boost gauge, the oem one was all over the place. Upon inspection, the ground for the transducer was loose. I tightened it anyway, but can the boost transducer affect other boost? Or does it sound like I may have a bad map sensor. It almost sounds like there is a leak (with the whooshing), but it might just be that I hear the turbo better with the K&N and ram air now...

i have the throttle jack and ebvp (?) solenoids both unplugged, and the vacuum pump is now plugged not going to anything (I am trying to find the heater control to run it too). Could any of this affect boost? I don't see why im only getting about 7psi (though twice, it spiked to over 15psi...

thanks,

Here's a pic of two connections that I saw disconnected... not sure what they go to... may be the prob.

http://studentweb.tulane.edu/~rjuge/images/01-12-05_1908.jpeg

[danny tattersall]

Hi, if you unplug the EPBV and throttle jack you will get a code 26. Also, if you unplug the oxygen sensor you will get error codes. In either case you will get a check engine light and as soon as this occurs it will limit you to wastegate controlled boost of about 0.6 bar. Hope this helps.

Danny '93 SE Highwing.

[Paula&Marcus]

Hi Rob,
The sound you are hearing is the well known "horsey sound". This always occurs when you back the throttle quickly while on boost (= when the throttle suddenly is shut close the still spinning turbo creates a backwave along with the wastgate opening that produces this flattering sound). If you have the Ram-air-mod (= silencer box eliminated) you will hear this sound quite noticable.

If there is an error code stored (Check engine light is on) your boost will be limited by the ECU to 0.6-0.7 bar for safety.

Cheers
Marcus (www.PUKesprit.de)

[country]

hi i have a 03 1/2 esprit,i get whoosing sound when i let off my gas also,i was told its normal,i dont have a blow off valve,i can hear it more when the windows are down.
adam