Last night, I was called to tow a 2008 Camry from a highway. The car engine suddenly died after start. The car owner then restarted the vehicle, but it flamed out again only two to three minutes later. This happened for several times, and the car owner finally called me for help.
I roughly checked the vehicle. It was with 98,000 miles on it and looked all good from the outside. According to the syndrome, the flameout could be caused by three things:
1. Oil lack
2. Ignition system fault
3. Other possibilities.
I connected the engine system to an OBD2 tool, Toyota TIS IT II, to troubleshoot the system, but did not get any DTC. Then I used an oil pressure tester to test the fuel system and got a result of 320kPa (as shown in picture above), which was within the normal range. Besides, there was no oil leak. Then I checked the ignition system. When I inspected the ignition spark timing, the result from the Toyota diagnostic tool was also normal.
Since the ignition system was fine, it was likely that the problem was caused by oil insufficient. I used Toyota IT2 to record the data before and after the startup, and found out the fuel injection pulse width was 1.92ms, 1.02ms less than normal.
According to the ECM working theory, the decrease of fuel injection pulse width was related to information provided by air flow sensor. I checked the air flow sensor and found its thermal fuse was covered by a foreign matter (as shown in picture above). I removed the foreign matter, and the car could be started normally then.