knocking feeling in gas pedal
 

Ok just curious if anyone knows what this is,
ive got a 1989 s13 coupe with a 1993 ka24de-t in it.
my steering wheel shakes when i go over 40ish mph, ive read a wheel balancing will solve that so thats happening this weekend.
So i do not know if they are related BUT
After accelerating and then just kind of cruising with my foot on this gas pedal but not pressing it down (coasting), i can feel the pedal vibrating/banging back and forth.
Any ideas what this could be? Will the wheel balance get rid of this? or is this a different more serious problem :(:confused:
any info would help thanks!