Symptoms:

This 2004 Kia Rio No Start happened 4 months ago while my wife was driving the car to work. She thought she heard an engine knock before the engine quit. Called a tow truck and took it to the dealer. Lucky for us, we had the dealer extended warranty and they have to fix it.

Ended up replacing the timing belt including all cylinder head valves. According to them only one valve was bent but they changed them all anyways. After this repairs, the car ran good until last week. All of a sudden, the engine lost power and would not idle past 2000 rpm? When we scanned the codes, we got P0340 for cam sensor fault code. This car is also out of warranty.

Diagnostics after 2004 Kia Rio No Start repairs:

Run the engine and checked the ignition timing and it was oscillating between 18 to 43 degrees BTDC. Measured the vacuum reading and it was on the low side at 16 inches HG which must be around 18-20 inches Hg for normal specs. Took the oxygen sensor out located before the catalytic converter (CAT) thinking maybe the CAT is plugged. Run the engine still the same.

Tested the cam sensor 3 wires for power and ground and they both measured OK. Thinking it had a bad signal wire to the engine computer(ecm), took the cam sensor out and bought a new one from the dealer. Before putting it in, we shone a light to the camshaft mounting hole so see if the reluctor is cracked but seems OK. Still the running was the same after replacing the sensor.

Getting desperate since we have no scanner to do a frame data measurements while the engine is running so we can check the engine computer. This way, we can check the integrity of the engine computer before replacing it.

Finally, from reading a KIA service bulletin (tsb), it was suggested to check and replace the crank sensor which we did and the engine took off like you would not believe!

Notes for 2004 Kia Rio No Start and later lost of power:

When we removed the cam and crank sensor, both read good in the voltmeter but the crank sensor has an internal problem that can only be measured by a labscope used by garages.

If the crank sensor will not fix it, the ecm and it’s wires would be next using pinpoint tests at the ecm terminals.

Please do not use this 2004 Kia Rio No Start ATS repair database unless you are assisted by a licensed mechanic from ATS or has the necessary automotive training to prevent engine damage.

Thanks,

Richard