Crank no start?

COMBS_CANDI

MEMBER
2010 HYUNDAI ACCENT
1.6L
4 CYL
2WD
AUTOMATIC
143,642 MILES

Car started fine when warm outside now that it is cold it cranks but no start. If it does start the engine runs perfectly.
I have replaced the crankshaft sensor, camshaft sensor, purge valve, 2 oxygen sensors, mass air flow sensor, MAP sensor, spark plugs, 4 coil packs, fuel pump assembly unit, starter, battery, throttle position sensor, and fuel cap. Have tested all the fuses. Also not throwing any codes.
What else could it be? Can you help?

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,867 POSTS

Hi,

These vehicles use the engine coolant temperature sensor (ECT) for many things. In this case, the signal from the ECT is used by the engine control module to determine how rich or lean to make the fuel mixture based on the temperature.

If the sensor is failing, it may be causing the fuel mixture to be too lean when it's cold resulting in a no-start condition.

If you have a live data scan tool, when the engine is cold, check the signal from the ECT to see if it seems to be accurate. For example, if it is 70 degrees outside, the signal should be very close to that. If it is 10 degrees and the sensor indicated it is 90 degrees, the fuel mixture will be very lean, and vice versa.

I attached a pic below showing the location of the ECT sensor. Let me know what you find or if you have other questions.

Take care,

Joe

See pic below.

Image (Click to make bigger)