Thursday, July 12, 2012

Engine turns over but will not fire or start?

2000 Dodge Ram 4x4 will not start.
When you turn the key ON,the engine turns over but truck will not start.
The fuel pump/transfer pump runs for few seconds when key is turned on,but will not start.

The Check engine light is ON.

FROM WHERE TO START TROUBLESHOOTING IN THIS CASE?

As you already mentioned that check engine light is ON.
So first step to start troubleshooting is get the error codes retrieved ,that are stored in engines computer module.
This error code will tell you what to inspect.
Get the error code scanned by scan tool.

OK,BUT I DON'T HAVE OBD TOOL TO RETRIEVE ERROR CODES?

At most of the major auto parts store,they do this error code scanning absolutely free for you.They don't charge for scanning.At autozone they do it for free.If there is any autozone parts store near you then you can get the codes scanned.

Also there is one more easy and simple method,that is manually retrieving the error codes without use of OBD scan tool code reader.

THAT'S GREAT.HOW TO RETRIEVE ERROR CODES MANUALLY?

Its very easy.The procedure is as follows.

Cycle the key from off to on three times ending with it on ( the sequence should be off-on-off-on-off-on)and watch the digital odometer display. Don't crank the starter, just off to on. The codes start with a P and have four numbers, there may be more than one stored. Once all the error codes are displayed the display will show done.
Note down the codes and list here.So further troubleshooting can be done from there.

OK.THE PROCEDURE WAS SIMPLE.THE CODES RETRIEVED ARE  P1693,P0336,P1690.

WHAT THESE CODES SAY?



P1693 sets in the powertrain control module when there is a code stored in the engine control module (ECM). If this was the only one that came up this way then there are still codes in the ECM that will need to be read with a scan tool or code reader.But in your case you also received other two error codes.So error code P1693 is not to worry error code.Its just the indication that there are more codes stored in ECM.

Now error code P0336 is for crankshaft position sensor a circuit range / performance.
Most of cases when error code P0336 is occurred,you will notice abnormal tach operation.It will bounce up and down and sometimes go dead for few seconds and come up again.


The P0336 sets when there is no crank sensor input seen by the ECM but it knows the engine is turning. Same as your case the engine is running but its not getting crank sensor signal.This can be the crank sensor or wiring but is usually the faulty crank sensor. The loss of crank sensor signal is also why the tach  drops out.

And error code P1690 is for  fuel injection pump.It says ckp sensor does not agree with the ecm ckp sensor.


The P1690 sets when the injector pump crank sensor doesn't match the other crank sensor's input. Inside the injector pump is a speed sensor that the ECM watches and compares to the crank sensor on the block. If the speeds don't match then the code sets.
So there are two sensors.One is injector pump crank sensor(also known speed sensor) and other is Crank sensor.The ECM(engine control module) receives signal from both crank senor and injection pump sensor.The reading should match,if the signal is not matching then you see error code P1690.


OK,SO WHAT PART IS TO BE REPLACED?


The error codes which you are receiving are directly and indirectly connected to issue with crank sensor.

It sounds like bad crank sensor. It would have set both of these codes and would have also prevented the injector pump from firing the injectors if the signal wasn't there. A wiring problem would be possible but not as likely, crank sensor failures on these trucks are very commonly noticed in such cases.

But before replacing the crank sensor,inspect its wiring connections properly.Test the voltage at its wiring to confirm that sensor is faulty,but wiring is not the issue.

HOW TO TEST CRANK SHAFT SENSOR WIRING?

Very simple disconnect the sensor first, then check for 5v, 5v, and ground on the three wires at the sensor with the key on. If these are ok then go ahead and replace it.If the voltage is not present,then its issue with wires getting short.Or problem with ECM.

WHERE IS CRANK SENSOR LOCATED AND HOW TO REPLACE IT?


The crank sensor is located on the left rear corner of the engine block.Its exactly behind the starter.Its like a connector,which you have to pull out.The connectors has 3 wires.First disconnect those wires and then remove the sensor. To access the crank sensor the starter has to be removed . The starter is held in with three 10mm 12 point head bolts.Once the starter is out,you can remove the sensor.

This details will help.
Thanks.


Users Who Viewed This Problem Also Viewed:

Brake warning light comes on and car will not start intermittently?

http://repairhelpcenter.blogspot.com/2011/12/brake-warning-light-comes-on-and-car.html

1989 Toyota Pickup Truck: Turns over but not start?

http://whatisbyme.blogspot.in/2012/05/1989-toyota-pickup-truck-turns-over-but.html

Car dead and will not Start?

http://whatisbyme.blogspot.in/2012/05/car-dead-and-will-not-start.html

2001 Toyota Prius will not start?

http://whatisbyme.blogspot.in/2012/05/2001-toyota-prius-will-not-start.html

1996 Jeep Grand Cherokee: Engine will not start?

http://repairhelpcenter.blogspot.in/2012/06/1996-jeep-grand-cherokee-engine-will.html

1997 Oldsmobile Cutlass Ciera: The Engine cranks but not start?

http://schematicsdiagram.blogspot.in/2012/04/1997-oldsmobile-cutlass-ciera-engine.html

Where is Crankshaft position sensor located on Toyota Tundra?

http://schematicsdiagram.blogspot.in/2012/02/where-is-crankshaft-position-sensor.html

Ford Focus Crankshaft Position (CKP) Sensor?

http://fordrepairhelp.blogspot.in/2012/03/ford-focus-crankshaft-position-ckp.html

How to test Ford Focus Crankshaft Position Sensor?

http://fordrepairhelp.blogspot.in/2012/03/how-to-test-ford-focus-crankshaft.html

For All types of Car models and brands help 
Go to Newly Launched

FREE Car repair guide? 
http://technoanswers.blogspot.in/2012/03/car-repair-guide.html 

& 
Complete Car repair Help FREE? 
http://repairhelpcenter.blogspot.in/2012/03/complete-car-repair-help.html