my volvo 240(1987) does not go beyond 70 mph though the accelerator travels furthur when that speed is achieved. i did a tune-up hoping the problem to go away, but it is exactly the same. so far i have changed the following:

* fuel pressure regulator
* coolant temperature sensor
* spark plugs, spark plug wires
* distributor, rotor
* oxygen sensor
* timing belt
* flame trap
* idle air control valve

** replaced some of the vacuum hoses
** clean throttle body
** clean injector by mike ponte's method
** changed all tranny, engine & differntial oils
** tried to adjust throttle sensor and throttle linkage

is my air mass meter defective?
my throttle position sensor faulty?
or throttle linkage adjusted incorrectly?

with all of the above performed, it did not changed the max speed of 70 mph.
the car idles better with the tune-up

thanks for any input.