Technical Car Experts Answers everything you need: engine backfire due to crank sensor

Crankshaft sensor location details

Testing crankshaft sensor before replacing it is advisable.

Crank sensor breaks or gets faulty and you notice crank issues and no start issues on your vehicle.

The crank sensor for rover is very delicate when used,so many a times it gets cracked,so remove the sensor out with care from its housing where its mounted.

The crank sensor is located down the back of the engine held with one small bolt - and has a blue plug usually.
The crankshaft sensor is located at the rear of the engine under the inlet manifold.

Its few inches above the driveshaft as it goes into the gearbox.
As per the details provided it is quite difficult to see and can be a pain to remove.
But its exact location is there.

If you locate the sensor and its very hard to remove,then please dont force to remove it with any other tool or screw driver.Just use wd-40 spray on it.The rust and dirt collected on the sensor area will get diluted and with slight wiggling you will be able to remove the sensor out.

Basic Procedure to test Crank Sensor

With the help of meter test for continuity of sensor from one end to another end.
If you get continuity these clears sensor is not cracked or broken in between.
Trace the wiring back from the sensor to the connection block should be fastened on a bracket next to the cylinder head.

Now once you get continuity test for ohm readings of sensor.Disconnect the sensor and connect the multi-tester probes to the sensor end of the wiring you should get a reading of around 100 ohms to 5k ohms if your get a reading above this or no reading at all either the wiring to the sensor is faulty or the sensor itself is

The Second test is with vehicle on and sensor disconnected .
Set the set the meter to AC volts.
Now probe the wiring at the sensor end and get someone to turn the engine over .
For a working sensor you get fluctuating reading of anywhere between 0.5v and 2.0v.
If this reading is not seen on meter then crank sensor is faulty.

The sensor looks like on the clutch side of the gearbox adapter plate.
See the Rover Crank sensor Diagram/image shown below:-----

These details and diagram will help.
Thanks.

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The very common cause of this problem on your Jeeps engine is the crank sensor,it sends a signal to the computer showing the engine is spinning,when this signal drops out the engine will shut down. It is located on the back of the engine at the bellhousing. See the image of the sensor,and another showing how it is mounted. It is accessed from under the vehicle.

Also check the ignition wires are routed correctly and connected properly to the plugs.And not got dirty/worn out or loose.

It can be faulty valve springs. Valve springs when get weak, they won't close the valves quick enough and backfiring is noticed. The only way to check them is to take them out and check each one. You could narrow it down by getting it to back fire and pull plug wires until the backfiring stops. That will tell you which cylinder has the problem.So you can continue replacing that cylinder.

This possibilities will help.
Thanks.

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