I have a 2007 buick Lacross with 104k miles on it. I'm having a random issue for a while now where it randomly does not like to start. it can range from a few minutes before I try again to start it to the next day. It's also having an issue where I hit the throttle and it will accelerate til about 40 and then wont go past it til I let my foot off the gas and hit the accelerator again and then it's fine. It is throwing up a long shift adapt code and is now rolling forwards and backwards in all gears but park if I push it any advice?

 

If no apparent cause has been determined,, might check out TPS on throttle body.
Some crank sensors will not throw a code, but can be intermittent, worth checking or just replacing it.
Can you tell if it is failing to upshift and then will if you let up on the throttle? If it is not shifting up you should see some pretty high RPMs.

You can always try a forced reset with the PCM , sometimes that gets rid of gremlins.

 

So I let it sit over night at work. Came back in the morning and fired right up. let it sit all day and tried to start it had no luck..

 

When you first turn the key on do you hear the fuel pump run for approx 2 seconds?

 

Yes I do I finally got it started and drove it up I noticed a hesitation at low speeds so I brought the car to a stop near my home and barely hit the throttle and it wanted to stall out.

 

What checks have you done so far?