Crank no start issue

Hi,

First, this can be the result of several things. The first thing that we need to do is determine if it is a fuel or ignition related issue. Take a look through this link:

https://www.2carpros.com/articles/car-cranks-but-wont-start

Here is what I need you to try. See if the vehicle starts for a couple seconds using starting fluid. If it starts and then stalls, we will know it's fuel related. If it doesn't even try to start, then it's likely ignition related.

Try that and let me know what you find. Also, let me know if this happened all at once and if there were issues prior to this point that could be related.

Take care,
Joe

Here's my situation:

I had the engine rebuilt from the heads to the block. I replaced everything else on the engine except the power steering pump with reservoir, the exhaust manifolds, the battery and starter wire harness and the ignition coil module.
I check the fuel system and it is pressurized. you can hear the pump when i turn on the key.
I did use a code reader and it's showing a crankshaft position sensor relearn code and ignition key theft code, but the security light is not on. And from my knowledge, the crankshaft relearn procedure is done while the engine is running.

Hi,

That is a correct. The relearn is done with it running. Also, it is a variation relearn.

You indicated the pump is running. Are you sure it is producing enough pressure? Have you checked for spark?

Let me know.
Joe

Fuel pressure is around 57psi. No spark.

Okay, that is where we need to focus. The most common cause of a no spark condition is a bad crankshaft position sensor. When it fails, you lose spark.

If you have a tachometer in the vehicle, check to see if it is moving at all when cranking the engine. If you have a live data scan too, check for an RPM signal when cranking.

Take a look through this link:

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor

If there is no RPM signal, chances are it is the sensor. If you determine it needs replaced, here are general directions.

https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

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Here are directions specific to your vehicle. The attached pics correlate with these directions. Note that this will require a variation relearn. I will provide the relearn after the directions. However, as I mentioned earlier, it will still run without doing the relearn.

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2006 Chevrolet Monte Carlo V8-5.3L VIN C
Crankshaft Position Sensor Replacement
Vehicle Powertrain Management Sensors and Switches - Powertrain Management Sensors and Switches - Computers and Control Systems Crankshaft Position Sensor Service and Repair Removal and Replacement Crankshaft Position Sensor Replacement
CRANKSHAFT POSITION SENSOR REPLACEMENT
CRANKSHAFT POSITION (CKP) SENSOR REPLACEMENT

REMOVAL PROCEDURE

CAUTION: Refer to Vehicle Lifting Caution in Service Precautions.


pic 1

1. Remove the right exhaust manifold.
2. Disconnect the crankshaft position (CKP) sensor electrical connector (1).


pic 2

3. Remove the CKP sensor bolt.

IMPORTANT: Clean the area around the CKP before removal in order to avoid debris from entering the engine.

4. Remove the CKP sensor.

INSTALLATION PROCEDURE

pic 3

1. Install the CKP sensor.
2. Install the CKP sensor bolt.

NOTE: Refer to Fastener Notice in Service Precautions.

Tighten the bolt to 25 N.m (18 lb ft).


pic 4

3. Connect the CKP sensor electrical connector (1).
4. Install the right exhaust manifold.
5. Perform the CKP system variation learn procedure. Refer to CKP System Variation Learn Procedure.

___________________________

Let me know if this helps. Also, let me know what code showed up when you scaned it.

Take care,
Joe

Well, I think I know what the problem is I actually replaced the original v6 engine with a v8 engine. The engine comes out a 2006 Monte Carlo . but the ECU came out a 2007 Monte Carlo. I was told by a dealership that the engines are the same for both years. So i'm thinking the issue is the ECU is not communicating with the crank sensor, cause i think the sensors are different .
If that's the case, i would have to installed an ECU from an 06 5.3L Monte Carlo engine, for which i cannot find one. and it would cost me $500.00 to get it re-flashed.
Any suggestions?

That is likely the issue. I was unaware of that. However, I attached a couple of pics below to check the sensor and circuit. Run through it and see if you find anything not working.

Let me know.
Joe

i'm only getting 5 volts to the 12v reference circuit on crank sensor wiring plug.
And if i unplug the crank/knock sensor harness I"m only getting about .5v coming out the main harness, so the chart leads to the ECU.

Check the supply wire from start to finish for resistante. The wire itself could be the problem. Or, check to see the voltage right at the ECM.

Let me know.
Joe