| Alright. I purchased a new vacuum gauge (see the videos below for the results). I also replaced the CAS sensor with the spare one that I had but that did *not* make a difference (so it's not the CAS sensor). Here's what I have found-out today: When the engine is held at 1500 RPMs then it seems there are no misfires and everything "seems" normal (or as far as I can tell). The vacuum gauge is also very stable at ~20 inHg (see the videos below). When the engine warms up and the RPMs begin to drop down to 750 RPM then that's when all the misfiring occurs (see the videos below for the vacuum gauge output). If I rev the engine back up to 1500 RPMs (or if I plug-in a 1.5k Ohm resistor in the coolant temperature sensor which forces the ECU to keep the engine RPMs artificially high at around 1500) then the misfires go away and everything "seems" normal. Any thoughts? Would a slipped timing belt cause such symptoms or am I barking-up the wrong tree? Could it be the O2 Sensors? How about the Inlet Camshaft Sprockets? Could they be worn-down internally whereby the timing is advanced/retarded improperly? Some info can be found in the description here:
https://conceptzperformance.com/bde-vtc-intake-cam-gear-sprocket-set-early-style-nissan-300zx-90-93-z32-bde-1000_p_3704.php
Here are the two new videos that I've made earlier today:
Engine when first being started (cold):
https://youtu.be/e2j1fg53R Around 1500 RPMs the engine "seems" to be working ok... https://youtu.be/sUOo7CO7en8
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01:54:26 08/25/20
