i wanna buy my friends 1991 sr5 v6 4runner, it runs fine but when you give it any more throttle then to just slowly bring the rpms up it falls on it's face and sputters and won't go above 2000 rpms. it can hardly drive because you usually need more throttle then a slight touch to get it up anything or actually accelerate at a decent pace.

i can even slowly bring the rpms above 2000 then give it more throttle and it still drops down to 2000

if you could help my that'd be great!

 

Id start with the basics. plugs, wires, cap and rotor. Id also do a compression test.

 

I spent lots of time figuring out the same problem.
The dealership could not find it either.
It was the fuel pump! My experience it usually works or doesn't, I was wrong.
Did not have enough pressure. The odd thing is it smelled really rich so I assumed
it had plenty of pressure.

 

yeah that could be it. but do you know where the fuel pressure check valve is? i'd rather check that then spend $120 on a new pump and find out that, that isn't the problem