Mitsubishi Repair: engine shutdown, eclipse spyder, temperature dips

Question
I have a '99 eclipse spyder that shuts down immediately after it is warmed up. The car runs fine for the first 3-4 minutes then stops as though it ran out of gas. After a cool-down period it will start again. I suspect a faulty heat sensor. Other than that I'm clueless. It won't run long enough to get it to the shop.

Answer
Rick,
Your problem very well could be with your engine temperature sensor.  If the sensor detects the engine is too hot, it will shut itself down.  The sensor is located in your thermostat housing (case), and costs about $30-$35 from the dealership. Part number: MD182467.  There is also a chance your water pump is not functioning properly.  If your temperature gauge in your car is reading HOT, then you may have a thermostat or water pump problem.

If you want to try to drive your car to the dealership or other mechanic, here are some things you can do, BUT USE EXTREME CAUTION!!  You can let out a few pints of coolant from your radiator and replace it with plain, distilled water.  Engines run colder when there is just water and no anti-freeze mixed in.  Also, you can remove your thermostat.  Without the thermostat, the coolant will constantly circulate, not allowing your engine to warm up fully.  Lastly, set your heater to HIGH and the fan on HIGH.  This will help cool down the engine.  All these things will make your water temperature sensor read colder; hence should let you at least drive to get it fixed.  Now, the tricks I mentioned above can cause serious problems if left like that; especially if you live in an area where the temperature dips below freezing.  It's also not good for the engine to run too cold no matter where you live.  After you replace your water temperature sensor (or water pump if needed), get a coolant flush and a new thermostat.
Good luck!