Trouble starting on 1994 Volvo 960

I inherited the car, no idea about prior maintenance. Sometimes starts right up, but often after being driven takes 10 -20 minutes before starts. I also do not have an owners manual.

Asked by for the 1994 Volvo 960
The engine coolant temperature sensors are a problem on these models, as well as vacuum leaks. First thing to do is check the codes. You can do this without any special tools, here are some instructions here: