Bad Crankshaft sensor?

[239]

I've had a problem for a few months now where the X wouldn't start once in a while. I had a shop look at it but they couldn't find anything and tests said everything was fine. Well the X finally wouldn't start today no matter what I did. So I went under the truck to look at the crankshaft sensor and I moved the wires around a bit. Well it fired right up.

Is it difficult to replace this sensor? I've read that it is, but it looks like it just bolts right into the engine. I tried to look for a harness to clean the contacts but couldn't see one. Any advice is appreciated.

 

[ranger7ltr]

It's not too difficult...

As I recall replacing the sensor is easier if you remove the serpentine belt first... But 2 bolts and one connector to remove, reverse it to replace it...Push the sensor into contact with the teeth on the harmonic balancer while rebolting up, connect it and replace the belt... Get up from under the front end of the truck and start it up...

Job done...

 

[239]

As I recall replacing the sensor is easier if you remove the serpentine belt first... But 2 bolts and one connector to remove, reverse it to replace it...Push the sensor into contact with the teeth on the harmonic balancer while rebolting up, connect it and replace the belt... Get up from under the front end of the truck and start it up...

Job done...

Ok. I've read about synchronizing them and also about gaps, etc. Maybe that was only on the V8.

 

[1998Exp]

Don't confuse the crankshaft sensor with the camshaft position sensor. It's the latter that needs to be synchronized.

Ok. I've read about synchronizing them and also about gaps, etc. Maybe that was only on the V8.

 

[imp]

Don't confuse the crankshaft sensor with the camshaft position sensor. It's the latter that needs to be synchronized.

In the older EFI, with plain old OHV engines, the camshaft position was not dealt with. I think the fact that those long timing chains were introduced led them to monitor camshaft position.

The crankshaft sensor provides crank location information to the PCM, as well as RPM. Location is needed to control ignition timing. The RPM is nowadays also used in conjunction with transmission input shaft speed, to detect Torque Converter Clutch malfunction. imp

 

[1998Exp]

In a four cycle engine the crank makes two revolutions for each firing of any given cylinder. With the waste spark system the crank position is sufficient to time ignition, but you need cam position to time the injectors - except for ancient central injection designs.

In the older EFI, with plain old OHV engines, the camshaft position was not dealt with. I think the fact that those long timing chains were introduced led them to monitor camshaft QUOTE]

 

[bstalcup]

No Spark, 2002 4.0

I have no spark, replaced crank sensor and it has 12v to coil pack, security light not flashing rapidly. Just did timing chains and cassettes. I found one wire to crank sensor to be 5 ohms to ground but I didn't pinch any wires.
Can anyone tell me where to find wiring diagram for engine or have any help you can give before I replace computer?

 

[239]

Don't confuse the crankshaft sensor with the camshaft position sensor. It's the latter that needs to be synchronized.

Ok. Thanks for clearing that up. So the crankshaft sensor is the one that's in front of the oil pan right? The one that makes contact with the crankshaft wheel? This is the sensor I'm referring to:

http://www.google.com/imgres?imgurl...d=0CCMQMygHMAdqFQoTCJess7rxzcgCFco8HgodUxYPWQ

 

[1998Exp]

Indeed. The camshaft sensor sits where a distributor used to be.

Ok. Thanks for clearing that up. So the crankshaft sensor is the one that's in front of the oil pan right? The one that makes contact with the crankshaft wheel? This is the sensor I'm referring to: