Help with humming noise when starting up '99 Explorer

[MEREALE1019]

When I start my '99 Ford Explorer Sport, it makes a loud humming noise, idles down, then stalls. It will start back up, and sometimes when I rev the engine a little, right before it stalls, the humming goes away & car is fine to drive. Only happens on start up & When I use the a/c. I was told it could be the fuel pump, but I got a new one & it's still doing the same thing. Any input would be great. Thanks!

 

[KPT]

Search for IAC. The humming is common. The stalling not so much but probably still the problem.

 

[Jstcruz]

Ive seen that on alot of the 97s (give or take a couple years) that the anti lock brake system will hum for a couple seconds on start up. I have no idea why they do that, and I dont think its related to your stalling problem. I would suggest disasociating the hum with the stalling and see what comes up.

 

[MEREALE1019]

We found where the noise was coming from. It is coming from the case that the air filter is in. Now we just have to figure out exactly what it is & how to fix it.

 

[Jstcruz]

Check your IAC. I just had to replace mine. To check it just unplug it and the humming will stop if that is the problem. If you have the 4.0, the IAC is under the cover on top of your intake