Subject: 1993 plymouth laser (eclipse) 1.8 5-speed
Question:

check engine lite on, ecm codes say four sensors bad; water temp, barometric, idle air control, intake air temp.CHANGED WATER TEMP and still reads bad code.hard to start cold,fires and dies, stumbles on acceleration, runs fine warmed up. Why would four sensors go out at once?
Is the a common relay or other thing affecting all four? Should I look for something else like low fuel pressure, plugged charcoal cannister, or vaccum leak?
Answer: Robert,
3 of those 4 sensors all deal with the intake system. The barometric and instake air temp sensors are both located in the air filter housing; and are known as the Mass Air Sensor (MAS). If your MAS has gone bad, that will set off several codes and cause the syptoms you described. You may need a new MAS.

You should also have your car's computer examined. Read this site for more information:
http://www.90gsx.com/eclipse/cap/caps.htm

If you ECU is malfuctioning, it will display error codes that should not really exist. Pull your ECU and check it for leaking capacitors.
Good luck!