Won't restart on hot days when engine is hot.

Greetings! Sounds like u have a bad coolant temp sensor. This is common. When it get hot out and the engine temp gets even warmer the resistance gets less and less. If the sensor is squeid in any way, the computor will think the engine is at a different temp than it realy is. Therefore it will give it less or more gas depending on wich way the sensor goes bad. Its not that big of a deal when the car is running because the o2 sensor takes over, but the engine temp is realy important when starting up your vehicale!

Relist: I still need help.
Replacing the coolant temperature sensor did not work. There is usually a certain time between shutting off the engine and restarting it that is problematic--approx 15 minutes. (Last time it was while grocery shopping). It is OK restarting after refueling--and always OK after sitting long enough for the engine to cool.

Edited by Customer (name blocked for privacy) on September 19 2006 at 12:27pm

Before we get into other things lets make sure you replaced the right temp sensor. There is sometimes two or three temp sensors. One for th dash, one for the cooling fans and one for the computer. Which one did u replace? How many wires did it have? and what color were they? Where was it located?

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Thanks for following up Amedee! As far as I know, I think I replaced the temp. sensor for the computer. There are two wires: Brown w/ Black stripe & Green w/ Red stripe. The one I replaced is located on the back side of the engine, on the left, and just below the valve cover. The sensor is almost impossible to see--it's view is obstructed by a main wiring harness.

What size engine?

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2.4L (4 CYL)

Good job! You got the right one.

So now we are looking at something different. Our next step would be to check the fuel pressure regulator. It is located on the fuel rail. It is round, about a quarter size and has a vacuum line going to it. If the regulator is leaking gas than it can cause this problem. Pull off the vacuum line that goes to the regulator. Be absolutely sure there is no gas in the vacuum line. If there is, the diaphragm has ruptured and there is gas entering the engine that is not accounted for and the regulator will need to be replaced!

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Thanks, Amedee. There is no fuel in the vacuum line that I can see right now--but I have not driven it in two days. I will be leaving to drive in an hour and will check for fuel in the vacuum line shortly after I shut the engine down.

There is no fuel in the vacuum line that I can see after running the engnie for some time. What do you recommend checking next? I appreciate your help, Amedee. (PS--after today, I will be gone 'til next month)

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