Going from the factory size bolt hole, 5/16" to a 3/8" hole on the Renix CPS (All my new ones have been aftermarket) and pushing the CPS closer to the flex plate (1/16" closer) while tightening the bolts, got me a 100% increase in cranking voltage, from about .25 to .50 on my 87 and 89 Renix rigs.
The one I tried the capacitor on had a cold connection inside the CPS between the coil wire and the sensor output connection wires. Took me 8 weeks to figure that out. It finally tested wide open one day with an ohm meter, 0.00 V, when it would not start, then later it worked again right after the ohm meter test, LOL.
The .047 mF Capacitor helped boost the CPS starting voltage but caused an engine miss at about 2500 to 3000 rpm IIRC. Or it may have been a higher capacitance one that did that, I forget. I think the Capacitor helped jump the cold wire to wire joint inside the sensor where the connection was defective. My last batch of good Renix sensors came from Rock Auto, Standard brand and Made in ITALY, NOT CHINA!!!!
But I still had to drill the holes out to 3/8" and move them in a tiny bit closer, 1/16" closer to the flex plate to get .50 V during cranking even with new batteries, and great grounds, new battery connectors.....Etc.
I posted pictures of the angel fine hair wire in the coil and the about 20 ga wire in the output wires and the cold joint (no solder, nothing) in the old thread.
No adjustment possible on factory parts, none needed either. And on 91 and later it's a Hall effect sender and you won't get any improvement... sensor's either dead or it isn't. RENIX uses VRM type CPS and you may get a bit of improvement, though Ecomike experimented with putting a small capacitor (0.047 microfarads if I recall correctly) in parallel with the two wires from the RENIX CPS and saw a significant improvement in signal output at cranking/idle speed, resulting in a faster start.