Just picked up a 1996 accord. Been sitting for a year. Runs good. Issue is the transmission. It may go a mile perfect then lose all the gears in the auto transmission. No reverse either. Cools down 30 minutes and pulls again. When completely cool, it never slips, gears change fine. Fluid level is good, doesn’t smell burnt. No engine codes thrown, no d4 light blinking. I’m assuming it is one of the solenoids, but which one. And should I try to flush before changing solenoid or after?