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Question

1999 Sonata. engine cuts off while driving and car still has power. If the car is moving it will come back on by itself, if stopped I have to restart it. It is like the key is turned to the accessory position.

Submitted: 40 days and 10 hours ago.
Category: Car
Value: $13
Status: CLOSED
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Optional Information

Year: 1999
Make: Hyundai
Make (other): Sonata
Engine: 2.4 4cyl

Already Tried:
nothing

Posted by AMEDEE 40 days and 9 hours ago.

Info Request

Hello!

 

When this happens, does the check engine light come on?

 

Are there any codes in the computer?

40 days and 9 hours ago.

Reply

no check engine light. There was a previous problem with the sensor that controls its shifting. It would downshift to 2nd gear then stay there until the car was turned off then back on again.

Accepted Answer

I would recommend to check the crankshaft position sensor. It could be bad causing your stalling issue.

 

CRANKSHAFT POSITION SENSOR
The crankshaft position sensor senses the crank angle (piston position) of each cylinder and converts it into a pulse signal. Based on the input signal, the ECM computes the engine speed and controls the fuel injection timing and ignition timing.

 

 

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Expert: AMEDEE
Pos. Feedback: 97.8 %
Accepts: 
Answered: 10/12/2009

ASE MASTER TECH

ADVANCED LEVEL SPECIALIST

40 days and 9 hours ago.

Reply

this would cause it to just shut off, then start back up again?

Posted by AMEDEE 40 days and 9 hours ago.

Answer

IT is possible! THats whay we need to check it to see if its bad!

Posted by AMEDEE 40 days and 9 hours ago.

Answer

ALso, you could have a bad mass air flow sensor. Here is a recall on this subject.

 

Recall 00V259001: Possible Engine Stalling

Some Sonata vehicles equipped with 2.5 liter V-6 engines and all Elantra model vehicles may have experienced intermittent low-speed engine stalling, which could occur if the MAF (Mass Air Flow) Sensor electrical signal is interrupted as a result of engine vibration transmitted to the MAF Sensor connector wiring harness.

This condition can cause the engine to stall, increasing the risk of a crash.

Dealers will re-route the MAF Sensor connector wiring harness.

Owner notification is expected to begin during October 2000. Owners who take their vehicles to an authorized dealer on an agreed upon service date and do not receive the free remedy within a reasonable time should contact Hyundai.

40 days and 9 hours ago.

Reply

this is the first time I have used this site. should I accept now or after I have tried? I have a 4cyl sonata which was purchased used, so I would hope someone who owned it before me would have answered the recall. Ill try the crankshaft position sensor

Posted by AMEDEE 40 days and 9 hours ago.

Answer

You can accept now and we can still continue our conversation if you have any further questions.

 

However, I would recommend to test both the crankshaft position sensor and mass air flow sensor before replacement.

40 days and 9 hours ago.

Reply

ok. what are the values that I should be looking for or am I just going to test for voltage?

Posted by AMEDEE 40 days and 9 hours ago.

Answer

Here is some info on how to test the crank sensor.

 

TROUBLESHOOTING HINTS


If unexpected shocks are felt during driving or the engine stalls suddenly, shake the crankshaft position sensor harness. If this causes the engine to stall, check for poor sensor connector contact.
If the tachometer reads 0 rpm when the engine is cranked, check for faulty crank angle sensor, broken timing belt or ignition system problems.
If the engine can be run at idle even if the crank angle sensor reading is out of specification, check the following:
Faulty engine coolant temperature sensor
Faulty idle speed control motor Poorly adjusted reference idle speed

 

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Posted by AMEDEE 40 days and 8 hours ago.

Answer

Here is some info on testing the mas air flow sensor.

 

If the engine stalls occasionally, start the engine and shake the MAF sensor harness. If the engine stalls, check for poor contact at the MAF sensor connector.
If the MAF sensor output voltage is other than 0 when the ignition switch is turned on (do not start the engine). Check for the faulty MAF sensor or ECM.
If the engine can be idle even if the MAF sensor output voltage is out of specification, check for the following conditions;
Disturbed air flow in the MAF sensor, disconnected air duct, and clogged air cleaner filter.
Poor combustion in the cylinder, faulty ignition plug, ignition coil, injector, and incorrect comparison.
Though no AFS malfunction occurs, check the mounting direction of AFS.




USING VOLTMETER

NOTE:


When the vehicle is new [within initial operation of about 500 km (300 miles)] , the mass air flow sensor air quantity will be about 10% higher.
Use an accurate digital voltmeter.
Before checking, warm up the engine until the engine coolant temperature reaches 80 to 90 °C (176 to 198 °F)

 

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40 days and 8 hours ago.

Reply

The tach always works. Ill try the crankshaft position and go from there and go from there. thanks.

Posted by AMEDEE 40 days and 8 hours ago.

Answer

SOunds good!

 

Please don't forget to hit the accept button if my answer has help you out in any way!

 

Please let me know if you have any further questions!

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