XDIME03

Hello all. Any help would be appreciated. I have a 1992 LX 5.0. When I start cold runs great drives good. After I drive for 15 mins or so when I clutch the rpm's jump up to 2k. Then after it starts that if I shut the engine off and it may restart its ok for a few minutes. Sometimes it does not want to restart as if the battery was dead. After sitting and cooling for a few minutes it will start back up again. Seems like something is getting hot. I was told possible iac valve so I replaced it but same condition. Not sure where to go from here.

mjr46

perform a base idle reset, check for vaccum leaks above all......starter may be getting heat soak