Dave Simmons

Hello i have a 1998 ford mustang 3.8 v6 that starts up and sits about 1500 then drops to 1300 then 1000 then finally like 800 after about 3-4 minutes is this normal? What could cause this and maybe some ideas how to fix? no vacuum leaks . i attached a video below. Thanks for any advice.

***VIDEO***

Dave Simmons

Throttle body is new MAF is new and IACV is new

dawson1112

Thats how its supposed to work. There is always a bit of a warm up cycle of the start up idle.

Dave Simmons

ok good to know just sounds really loud didn't sound right and since its every time i start it and not just when its cold i wasn't sure thanks

Jimmie Rae Sample

It's normal to a point but not if its really loud like that's a sign of it being too high in rpms... along with the really high rpms and loudness mine also cut out really bad too as i would take off and speed up through each of the gears too as the rpms got higher with each shift.... it would cut out. I changed my plugs wires all the above and it was still doing it..turns out the new map sensor that was put in it was faulty..cuz when I unplugged it all together it completely quit doing that all together...slight rev up upon start but not so much so that it was loud and it went down really fast too...and when the new sensor was put in... works great and still no loud rev ups...u might try a different sensor..its always possible that u got a faulty one