Quote:
Originally Posted by big_windy
I measured old sensor and find they are the same length so appears I have correct new replacemnt, and provided depth of new timing chain cover well is same, should have same air gap as original set up.
I put a probe wire into back of CKP connector at yellow wire and cannot see any AC signal while cranking. Lowest setting on my multimeter is 200VAC. Would an analog meter be better to use? I confirmed Battery voltage on the pink wire and ground on the PPL with key on.
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All of your test results in post #13 are correct. Battery voltage on the pink wire and ground on purple, (at the CKP) means both of those circuits at the CKP are good. Your resistance reading on the yellow wire is good, which means the PCM can receive the pulses... if the CKP is producing them. When the starter is cranking, the CKP creates a magnetic field. When the crankshaft rotates, the reluctor wheel changes the magnetic field. The CKP sensor converts the changes into pulses and are measured as a duty cycle with a Digital Volt Ohm Meter, (DVOM) capable of measuring Hz, (cycles per second). When the engine is cranking, the duty cycle should be 40% to 60%. So, with what you have checked, and the results you got, we can be pretty darn sure the CKP is not producing the pulses. The ONLY way to know for sure is to check the duty cycle. As I mentioned in an earlier post, if the air gap is too wide, the reluctor will not change the magnetic field and no pulses will be produced.
Something to check: Rotate the crankshaft manually until one of the teeth on the reluctor lines up with the CKP sensor, then measure the air gap with a feeler gauge and post your measurement. In the meantime, I'll go measure a "known good" air gap on a 4.3L. If your air gap is out of spec, the problem might be the new timing cover is not orienting the sensor correctly.
EDIT: AC voltage across the yellow and purple wires while cranking should be at least 20mv, and the air gap should be no more than .050" ...from a pretty reliable source
