I'd bet your AFC is fucked. I assume you checked the settings on it to make sure it didnt somehow reset itself, so that isnt it. Might want to bust open that panel below the shifter, and check your connections again. While your at it, you may want to solder them like they should be.
Remember when we first put the AFC's in the cars Sanj...one of mine had an awful connection and yielded similar results. My car just choked down the street until it was properly connected.
2.5 miles from the house...hmmm that could only mean ONE place
Another thing i was thinking was maybe just a bad end tank of gas you had in there. Did you try refilling the tank and see if the problem persisted? Long shot there but worth a try.
If you cannot figure it out, put it on a truck, and send that VR4 to MEEEEEE!!!!
Good Luck Cub Fan