That sensor on the drivers side of the motor between the plugs is the knock sensor. On the passenger side of the motor between the plugs is the temp sensor for the gauge. The 2 wire sensor near the t-stat housing is the temp sensor for the ECM. Korey.

 

Ok... Well, I am consolidating the threads on this topic back down into this one. I cannot merge the threads (would be nice if I could) so here are the links to the locked threads that were floating around:

Blazer cranks but wont fire
cracked gas line
white plug (sensor)??

And another related thread that I haven't locked:

WooHoo! I got it started, but still need a part name

 

I installed a coolant temp. sensor in the place of the ECM sensor.
Could this be a reason my Blazer wont start?

Im working on spark and fuel now but I figure3d I ask. Thanks

 

Well my check shows I have fuel and I replaced the plugs.
I got it to start again and it idles somewhat smooth but when I give it gas it sputters and doesnt run well and trys to die.
It makes a zingzingzingzing which sounds and feels like it is coming from under the distributor cap..
I replaced the cap and rotor but it sounds like the mechanism underneath is rubbing hard or burning out..
Any suggestions what this might be and could it be the reason it is not firing and running well?

 

There is a Camshaft position sensor inside the distributor and if this is failing then the timing would be off. It needs to synchronize with the Crankshaft Position Sensor that is located on the end of the crank near the front oil pan seal...you should see a connector with wires coming from the end of the crank...if the two sensors can not synchronize then you could have a no/hard start condition...

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