2009 Chevrolet Lumina LTZ random acceleration problem and Cruise Control

I have a 2009 Lumina LTZ 3.6L with 2 main problems...

1. The acceleration suddenly stops randomly when my feet is on the pedal. This
happens between any speed... 0-60 or 60-100KMPH... It happens completely random
to me which is why I fail to explain it to any technician. The tech said there is no error
code so he cannot do anything. I have to raise my feet off the pedal and give it another
go to engage acceleration.
Its not like the acceleration doesnt work at all.. .maybe it goes 0-60 or 70 and then
stops reving... I will have to give it another go to continue... ANy idea what this could
be?

2. My cruise control does not engage. The visual indicator says Cruise On, but it does
not say Cruise Active. Earlier, it used to say Cruise Active but it used to dis-engage 5-
10mins later. Now it doesn't go active at all. The tech again said.. no error code for this
so cannot tell.

They usually recommend some random part to be replaced but they are not completely
sure if that would do the fix and result in a hefty bill. Any insight on these problems
could help me alot. Thanks in advance.