Dies at stop signs, seems low on power
 

I have a 1994 Bonneville that sat over the winter. When I parked it, it had plenty of power and ran perfectly fine. It seems like it's low on power, when you stand on the gas it won't jump into passing gear. It also dies every once in a while when you get off the gas while your approaching stop signs or stop lights. It always starts right up and you can go on. I also notice while sitting in my driveway over the weekend that the idle throttled up to 3,000 rpms for a few seconds and then came back down. It seems to run fine once you get going down the highway.

Any ideas without me having to take it to a mechanic?

I'm thinking it's either your TPS(Throttle Position Sensor) or your MAF sensor(Mass Air Flow)
Do you have a multimeter?

Clean the MAF, inspect and test the coils, change the plugs, check the plug wires.

Do these cars have Idle Air Bypass valves? This was a common problem on Ford's 4.6's.

MAF was the problem on my 97. This also threw the SES light too

At a stoplight, the pcm will be controlling idle through the IAC based on MAF readings etc. While you are cleaning the MAF, clean the IAC as well and check the throttle plate/linkage for free movement.

You might check the air filter as well to ensure no critters piled nuts in there that might restrict airflow.

If it sat for a while it could be the gas try a new fuel filter and fresh tank of gas.