Hi everyone so I got this 2000 Mazda b4000
and I’m having issues with it I can’t seem to get it started it turns over fine but there is no spark and I found there’s no power going to the crankshaft position sensor not to sure where to go from there any help would be great and also there’s no pcm relay

 

Welcome to the forum

2000 B4000 has a 4.0l OHV engine

Crank sensor generates its own voltage, 0.5vAC(cranking) up to 8vAC at high RPMs, so AC volts not DC volts, no voltage goes to the crank sensor

Turn on the key
CEL(check engine light) should come on, that means Computer has powered up, no CEL means Computer is OFF, blown fuse maybe or bad relay
Crank engine over, CEL should go OFF, that means Computer is getting a good timing signal from Crank sensor

Hard to test for spark on Waste Spark systems, spark testers are hit and miss
Best test for any gas engine is 50/50 test
Spray fuel into the engine
Try to start
If its starts and then dies you have a fuel supply issue
If it doesn't start then its a spark issue
50/50 instant results

 

Hey Ron thanks for the help I have tried spraying fuel into the engine and it did nothing and the CEL stays on when turning the key as well

 

If CEL stays on while engine is cranking(turning) then replace Crank sensor and follow its wires as best you can up and into the main wiring harness, looking for damage

Crank sensors rarely fail, but rarely is not never
Crank sensor reads a "tone wheel" just behind the crank pulley, it looks like a gear but touches nothing, the crank sensor is close enough to it to "see" each tooth as it passes by, there is one Missing Tooth, that gap denotes #1 TDC, thats the timing the computer uses to start spark and then fuel

Make sure tone wheel is clean, no caked mud between teeth, and not damaged, no broken teeth, just the one missing tooth

Crank sensor is a Variable Reluctance(VR) sensor
A VR sensor generates an AC voltage when metal is passed by it, so as each tooth on the tone wheel spins past it, AC Voltage is generated, 0.5 to 0.8vAC at cranking speed(200rpm)
The AC voltage is not the signal, just a by product, the signal is the Sine Wave that AC voltage has, the wave as voltage goes up and down, and then "the gap" when it doesn't