I just finished installing a new (not rebuilt) alternator in my 2002 Rodeo base with the 3.2L V-6 engine. This was a proactive move since the vehicle is 21 years old and has 172K miles. The DashCommand app on my phone shows that the new alternator has an output of 14.2-14.4 V.
I also cleaned the throttle body and MAF. My records show that the last time that the throttle body was cleaned was Oct. 2011, more than 10 years ago. I may have cleaned it since then, but it is not in my records. The MAF was last cleaned in Oct. 2015, about 40K miles ago. It might be my imagination, but it feels like the car accelerates better and the throttle is more responsive.
That’s the good news. But there are a few things happening that I do not understand. First, I have only started the engine twice since finishing this work. Both times the starter spun for a prolonged time – maybe ~10 seconds – before the engine started. The engine is running fine, the coolant temperature is 180-190°F and there are no engine codes. But the engine initially idles around 1,500 rpm and then drops down to the normal 800-900 rpm (with AC on) over about 30-60 seconds. Could this have anything to do with the PCM adjusting itself since the battery was disconnected along with cleaning the throttle body and MAF?