Why would your car not accelerate beyond 20 miles an hour even when you step on the gas in a manual transmission?
Could be a plugged catalytic converter, bad air or fuel filter,
or a weak fuel pump
Sounds like your clutch is worn out. Listen to the car and see
if the engine revs up when you do this. If so, your clutch is
slipping and you need a new one.
it also could be your cap and rotor going out if you are gunna
replace these might as well spend a few extra bucks on plugs and
Try shifting into 2nd.