I installed the Paxton SN89 blower on my 93 5.0 Coupe. Only engine mods to the coupe are a Typhoon intake. Well the install went well and the car runs fine, but after it idles for about 20-30 seconds then the idle drops down to around 700rpm and it has a lot of lope to it. Sounds almost like an F-cam. The car still has a stock cam and had no lope to it before. Driveability is still great and it doesn't have any miss or skip to it about idle. What could be causing this?