Thanks for all the information. Here is my update.

I know enough about the ignition switch that if it or the fuse to it is bad, you will not get dashboard lights. I have dashboard lights so I'm checking off the I.*. and fuse. Third, I don't believe its the neutral safety switch.
Fourth, battery is full charge. That'* how I got to Pass Key 2 or Starter/Starter fuse/or loose cable to starter.

When I got there yesterday, I put the key in and realized there was a sound when I turned the key. I could here the
clicking come from the starter with no security flashing on the dash. But I could hear the starter so I kept retrying and it did start so I checked off Pass Key 2 and am zoning in on a starter related issue I got the car home and tonight got only clicking from the starter with full battery charge. So I'm down to starter itself being shot or the positive battery cable to it being loose. I guess I'm going to have to get underneath and hit the starter with a hammer to get it started. Fuse to it should be good because power is getting to it. I would like to remove the positive terminal, clean it and then reinstall.

You still don't know how that switch works. I'm not saying the switch is bad but you can have lights with a bad switch.

You are going in the right track. Starters/Solenoids fail after many years of use!

Hi Folks,

Good news, this morning I attempted to start the Lesabre and got that same clicking sound with power to but no spin of the starter. From the sound, I got a feeling something wasn't connected right so I started at the top with the positive battery terminal and took both off and cleaned and re tightened. Started right up.

So it was a bad connection somehow. The cable wasn't loose but maybe dirty or not fully seated. I've started it multiple times and its fine. My other problem I mentioned about hesitation or a dead spot under heavy throttle load still exists though. I was hoping the bad battery connections were causing this as well but I don't believe so.

Hit the gas fully down and stifled response. I'll do the c. converter test to see if its a plugged exhaust and then a fuel pressure test to see if that is low. All of this is completely original from 1992, never touched. Possibly a bad throttle position sensor?

If any of you want to see the car its on YOU TUBE, go to 1992 Buick Lesabre Limited, its the grey one with vinyl top.

I'd look at the fuel pressure regulator first. If it doesn't react well to the vacuum surge of opening the throttle all the way, fuel pressure won't rise when it should and you'll see this.

after checking fuel pressure. If it'* normal, you might want to check the IAC valve (idle air control) it'* on the throttle body. they get dirty. you can take it out and clean it but before you put it back in make sure you depress the plunger.

Here is my update. I checked the fuel pressure regulator and found plenty of vacuum and no fuel leaks of any kind. Then I checked the fuel pressure at the schrader valve. Key on, engine off, pressure went straight to around 43 and then immediately went to zero. No leak down test needed at this point as pressure was not maintained at all. I then started the engine with pressure maintaining a little over 40. Keep in mind the last time I drove it on Saturday, when it was fully warmed up, I experienced the hesitation across all speeds and rev ranges. The engine was struggling for power as if starved of fuel, not missing as in a bad coil pack but instead as if running out of gas.

While still running and at 40 PSI, I disconnected the fuel pressure regulator and PSI spiked a bit as it should and then went back down when I reconnected the vacuum hose. So I removed the regulator from the equation.

When I turned the engine off after running for about 10 minutes, the pressure went immediately from around 40 straight to zero. Is there anything else this could be beside the fuel pump?

Original fuel pump, water pump, exhaust, and a/c compressor-29 years old 141,000 miles. First tune up last September 2020.

Makes me wonder if there'* a piece of crud in there, like if you pull the pressure regulator you'll find something there on the seat.

Yes, I was thinking the scenario was odd so I will pull the regulator and see if its gunked up. What is the quickest way to pull it out, isn't there a snap ring holding it in place? Easy way to remove?

It'* the pump.