1995 Lexus Ls400 Coolant Temp Is About 240° F And Takes A Long Time To

[thomasf]

I have a 1995 Ls400 that had 241k miles on it. I have trouble starting it. I have to keep turning the ignition over and over and after a while it will start. When i press the gas pedal after it starts for the first time it dies and i have to start it over again. After a while it will start again and stay on and be drivable. I used a scanner to check and it said my coolant temperature was 242° F. I don't know why it says it's so hot. Any solutions?

[landar]

Well I could almost guarantee you that it is not 242 F so it is most like a faulty temp sensor 'fooling' the computer, resulting in a too lean fuel mixture for a cold engine. What kind of scanner did you use?

Welcome to the club, Tom!

[gifted-tulip]

If your check engine scanner reads 242 degrees, the coolant temperature is way above boiling. The engine temperature should be 160 - 180 degrees F. when warmed up. Maybe your coolant fluid is low in coolant reservoir. Let the car engine cool down completely 2 - 4 hrs. and then check coolant level in coolant reservoir that is close to coolant radiator Have you checked whether your coolant reservoir is filled to the proper level? After filling the coolant reservior, start the engine and let it warm up at idle and then do a diagnostic code check again. If the temperature is still above 180 degrees, you may have a faulty thermostat or cooling fan or fan belt problem that needs replacement.

Secondly your starting problem may be due to faulty fuel pump or a plugged fuel filter in gas line. I would suggest replace the fuel filter first to see if this fixes your problem. Then have mechanic check fuel line pressure at the engine. Maybe you have dirt in your gas tank and you need gas tank removed and cleaned of all debris.

[curiousB]

Short circuit engine temp sensor or associated wiring. Check that first. The ECU will lean out the engine thinking it is warm when it is not. That is why it behaves better when warm, the ECU isn't "as wrong" it its temperature assumption.

Unplug sensor and measure resisatance with a DVM. Try the test below. Sensors like these typically fail to an open circuit which would be a cold temp reading and a rich engine all the time but maybe yours failed to a short.