Hello , I have a friend (old girlfriend ) who has a 87 300 E that starts fine and runs well untill its fully warmed up then starts running real bad or not at all . When you allow the car to cool for a hour or so then it starts up fine again . My guess is that there are a number of modes on warm up that are working fine untill it gets to full warm mode . Sensors ? thermostat ? something that is supposed to tell the computer that all is warm now we are at operating temp is not working right . Anyone out there with any experience with this , all ideas are greatly appreciated . By the way I have a 83 300sd with 275,000 miles that runs great . I have never owned a car that felt so good to drive . Darrel in Beaverton Oregon . djohannes96@gmail.com