4 cyl. auto trans., 362K miles. On a hot summer day (105 - 110 degrees)after the car has run for awhile with the air on it will suddenly quit as if the ignition was turned off. The engine temp is just below center gauge and there is no boil over when stopping.

The engine will restart after a cool down of 10-15 minutes with the hood up and is good for another 10-20 minutes of driving till it quits again.

There is no CEL.

The EFI relay, fuel filter, and fuel pump have been replaced. I installed a volt meter on the fuel pump plug to monitor voltage to the pump while I'm driving. When the engine compartment heats up and it quits, there is full voltage at the fuel pump plug until the engine comes to a complete stop and then the voltage goes to zero when the ECU loses a signal from the crank sensor.

After rolling to a stop, I tried cranking the engine and the volt meter shows the fuel pump is getting voltage while the key is in the start position.


The EFI relay is energized when the ignition is on and powering the system.

After stopping, I tested for spark at the plug wires and all 4 wires are getting spark. I also carried a small bucket of ice water and a rag and tried cooling the fuel filter, the throttle position sensor, the distributor capacitor, and the relays in the main relay box. Nothing shortened the 10-15 minute cool down before the engine would start again.

This is reminiscent of the old days of vapor lock but I haven't had that experience since the advent of electric pumps and return fuel flow systems.

Would appreciate any suggestions on where to go from here. I would also like to know if anyone knows of any high temp sensors for engine compartment fires that would shut down the EFI via the ECU, or the loss of any other signal that would have the same effect.

 

There are no high temp sensors of any kind linked to shut down the engine.

At what times does the engine quit, stops lights and signs, hwy, both?

Do you have the A/C on and thus the ECU inside passenger compartment is kept at a reasonable temp?

Get a few cans of freeze spray. Its C02 in a can, when sprayed it cools whatever the spray contacts. See link below for one product. Prices vary from OK as at Walmart to expensive so shop around.

Max Pro FR Blow Off Freeze Spray - Walmart.com

When the engine dies try spraying one at time on the:
-ignition igniter
-coolant temp sensor for engine ECU
-ambient air sensor for ECU, fitting to air intake filter box
-engine computer, behind glove box
-remove distributor cap and find the ign pickup coils inside, spray the coils

There should be a small plastic box under the hood perhaps mounted on a strut tower. Inside the box are electrical terminals. Find the FP and B+ terminal. When connected with a wire, the fuel pump will run when the ign key is on. This will bypass the fuel relay.

When engine dies, try applying throttle when trying to restart.

Check spark quality engine hot and cold. Should be a white spark and able to gap 1/2 inch of air.

Checking wiring harness plugs, etc at computer and other components. Sometimes a connection is OK until it gets to hot.

Suggest getting a Haynes service manual covering this year of car. Cost is under $20, less if used. It has data on testing sensors, and other components. Then you can test them hot and cold.

 

Thanks to everyone for their help. The problem is the fuel pump, or something else in the tank. I used all the suggestions here and the final test was to drive up one of the local 12 mile grades (6-7%) when it was about 110 degrees and the Camry quit about half way up the hill.

I energized the pump with the OBD I connector to see if I could hear the pump running, and it was, but the car would still not start.

I had packed a 2 1/2 gallon gas can in an ice chest in order to cool it and carried it with me in the trunk.

I disconnected the jumper to shut off the pump before I added the cold gas, which was around 37 degrees, to the tank to cool down the pump and small amount of gas in the tank. As soon as I finished emptying the cooled gas into the tank, I immediately tried to start the car and it fired right off. I then finished the rest of the trip up the grade and back down again and the Camry never stalled.

Thanks to all that helped out. Once I have this pump replaced and out of the car, I'm going to experiment with it at different temps to see if I can determine exactly what went haywire and I'll post whatever I find.

 

Please post back with the results.