Rav4 1999 hesitates and loses power

so the throttle fails, in Park too? or neutral or in drive.
we need to know all facts here.
the throttle adds air the EFI measures that and adds fuel.
then RPM rises, to 3000 rpm easy in park.
does it do that?
then fail to make power in drive.? power is in move car?
check fuses first.
then scan it. using any scan tool works on all USA 1998 and canada. cars.

or "then it starts to go"

my guess now is ,that car drives ok, but has a small hesitation
and has full power up any hill wide open throttle and the transmission does not slip.?
is that it?
that can be a bad TPS sensor. (hesitates then catches up)

what is the delay time, from ignoring right foot to go.
1sec, 1 minute, what?

could be lose timing chain/belt. or timing off, bad plugs or related.

is the check engine light on? check for mas air flow sensor

If the check engine light is not on, I would check the fuel pressure and for vac leaks.

Obtain a Hayne's Manual for you Make, Model & Year vehicle. In the beginning of the book, they have a troubleshooting section.

you may need to get your injectors cleaned the fuel filter being changed is good the coil is another good one or your fuel pump could be weak and isnt giving the proper psi of fuel to the injectors so id say clean the injectors first if thats not it the fuel pump

If you don't have a check engine light, Start with the air and fuel filter, work your way up to a tune up. Clean the throttle body as best you can on the inside, behind the throttle plate/s

check air flow meter . when car is at idel disconect wires and if tone changes with engine then its fine but if no change then it needs replaced hope this helps?

altenator or battery going out, also check all grounds to motor and body!

Did you check earth connection of electric system?