86-86 2.9 throttle body.

[rickcdewitt]

you'll notice its way jerkier in 4low and really just opens the throttle faster with the same amount of foot. so you reach the point where more throttle does nothing even faster.

 

[RustedRanger]

I have learned after owning/driving many different fuel injected cars/trucks to learn what the motor wants as far as the gas pedal. I have only "floored" my 87 2.9 a couple times and it is a waste. I usally "roll" on the throttle giving the engine what it wants and I can tell that by how hard it pulls. The other day after finally getting it to run good I revved it to 4000 before shifting and it did so very easily and only seemed to need a little over half throttle and it pulled hard and revved quickly. I just smoothly increase the throttle as RPMs increase. More aint always better

 

[Maverick]

so you reach the point where more throttle does nothing even faster.