Harmonic balancer

The toothed tone ring for the crankshaft position sensor is on the back side of the vibration damper. When it came loose, the sensor had no teeth and gaps to detect, so it stopped developing signals. To the Engine Computer, the lack of signal pulses means the engine stalled. The computer doesn't know why the engine stalled, but since one possible cause is a fuel line was ruptured in a crash, the computer turns off the fuel pump to stop dumping raw gas on the ground.

By wobbling around, the teeth on the back of the vibration damper likely hit and damaged the crankshaft position sensor. Start by looking at that. This photo shows both parts. The blue arrow shows where the damage will occur to the tip of the sensor. The red arrow is pointing to the teeth that are detected by the sensor. Note there are some uneven gaps between them. Those are how the computer determines which piston is coming up on top dead center.

The next step should be have the diagnostic fault codes read and recorded. The people at most auto parts stores will do that for you for free, but obviously you have to get the truck there. The good news is for this basic task you don't need a full, very expensive scanner. A simple code reader will do the job. You can find them online and at places like Harbor Freight Tools, Walmart, and farm and home stores. You might check these out too:

https://youtu.be/XY-1CsAzrFA

https://youtu.be/jr_Iv8T_Phk

Most code readers only read codes in Engine Computers. This second one can also access Air Bag and Anti-lock Brake Computers.

One thing to be aware of with crankshaft position sensors and camshaft position sensors is it often takes some time for a missing signal to be detected, as in when a stalled engine is coasting to a stop. A fault code for one of them may not set just from cranking the engine. When that happens, you do need a full scanner to view live data and see what the Engine Computer is seeing and responding to. Normally both sensors are listed with some type of notation as to whether their signals are showing up during cranking. If one is missing, the computer will not turn on the fuel pump, and usually spark too.

It's hard to imagine some other defect would show up just at the time the vibration damper came loose, but anything's possible. Hopefully there will be a fault code to direct us to the circuit that needs further diagnosis.

Remember, just cranking the engine often won't set a fault code for these sensors. That's when you need the scanner to see if the computer is seeing those signals during cranking.

Looking for fault codes while cranking isn't the right approach. If one would set during cranking, it would be there all the time and could be read by your code reader. All fault codes have a long list of conditions that must be met for them to set. Often one or more of those conditions isn't met during cranking, but the missing signal still causes a crank / no-start. This is why you need a scanner to view live data. My Chrysler DRB3 lists the camshaft position sensor and the crankshaft position sensor with a "No" or "Present". They'll both be "No" with the ignition switch on, then they must immediately switch to "Present" when the engine is being cranked. If one stays on "No" during cranking, that is the circuit that needs further diagnosis, even though it didn't set a code.

I'll be waiting for your update. I still think this is related to the harmonic balancer problem. It would be unusual to have two different problems at the same time.

CARADIODOC is one of our best! Use 2CarPros anytime, we are here to help. Please tell a friend.