93 Thunderbird help

1993 Ford Thunderbird with 150k miles on it. When starting the car I would have to keep my foot on the gas to prevent the engine from dying until it warmed up. I figured it was the idle air control valve so I replaced it and while the engine runs fine now there is a very loud lawnmower-like sound coming from the throttle body air intake tube. I thought that I might have bought a faulty idle air control valve (Duralast brand) so I got another one from AutoZone under warranty, but the new one had the same problem. Ended up returning that one and bought a Delphi IAC from RockAuto. Same problem... When the electrical connector is disconnected from the IAC the noise goes away but the engine has problems idling when it's cold. Any ideas what this could be?

Anyone has any ideas on this one? I took a look at Ragetrain's car a week ago or so and if the IAC electrical connector is plugged in, the IAC makes an extremely loud lawnmower noise. As soon as you unplug it, the noise goes away, but then you have problems with the car idling. Tried three different new IAC valves without success, they're all noisy (one sounds like a foghorn on a ship).

Is this a five litre? If so, the problem may be with the mass air sensor on the intake throttle body. i had a similar problem, so I opened up the sensor module (after buying the necessary tamper-proof bits) and found that there was a build-up of corrosion on the thin wire thread-like element. Using an electrical parts/sensor cleaning spray, I cleaned up the sensor and the issue was solved. If there is any problems with this sensor element, it can cause any number of issues with air/fuel intake. Also, have you checked the intake resonator box for obstruction?

hope this helps

**p.s. I should mention that my car is a 1993 t-bird lx 5L H.O.

His car is the 3.8L V6. It's not the resonator box nor the MAF. Removing the air intake tube that runs between the throttle body and the MAF that's connected to the resonator box doesn't make the noise stop. The only thing that stops the noise is disconnecting the idle air control valve's electrical connector. We'll give it a try though... Thanks for the idea!