I have a 1999 Bonneville SLE with the 3.8 L engine. A little history with my problem:

A while ago, my car died twice. Once while at a stop light, and once while driving down the street. My check engine light came on, and after the one incident it didn't die again for a few weeks, and in fact, my check engine light turned itself off.

A few weeks later, the car starts dying again, this time dying five times within 30 miles. Every time it happened, it was when I would start to accelerate after stopping. The check engine light and the check gauges light came back on and stayed on. I had a mechanic look at the vehicle, and he couldn't get the car to "trip" [as he called it], so he said it was pretty hard to identify whether it was the crank sensor or something else. We talked about it, and I just told him to replace the crank sensor anyway [because it'* the most logical solution] and hope for the best. When I got the sensor replaced, the check gauges light turned off, but the check engine light has continually stayed on. Not sure if the mechanic just didn't turn the light off after he fixed it, or what. The car didn't die again, but the check engine light remained on. Yesterday, the car died again...however, the check gauges light didn't come on this time. I restarted the car, and it didn't die again.

One thing that is always consistant whenever my car dies: the car is always at 1/4 tank of gas or less. When it gets that low, the gauges for my battery and oil level and whatnot will really float around, and if the car'* going to die, it always happens then. When my car has had more than 1/4 tank of gas, it doesn't act goofy at all.

So...that brings me to ask...does ANYONE have any idea of what'* going on with my car? I just had the crank sensor replaced, so it'* obviously not that causing the problem. And why does this only happen when the car is at 1/4 tank of gas or less? I'm at a loss. HELP! Thanks in advance

Best we can do right now is to have you retrieve any stored codes that are in the PCM. Even though the light went away, you will have a stored history code. This might help us identify what is going on.

I'm not sure why being below 1/4 will have an effect on some of your gauges, but you said you can reproduce the dying results with 1/4 or less? I'm suspecting you may have WAY less then 1/4 tank of fuel. If after you get on the throttle from a stop, the fuel will slosh to the back of the tank and will no longer be near the fuel pickup. Thats what I'm suspecting.

Something to look for in the future while we ponder this is, when it happens again, listen for the fuel pump. Does it still prime immediatley after the engine shuts off? Turn power off, then back to run, does it prime again?

Because you have a 99, and also not sure where your located, but checking this out would not hurt.
https://www.gmforum.com/showthread.php?t=278980