They can be adjusted. Trying to find the specs and test procedure. On here or some other site... ... ... ... ...
Edit- Just noticed your engine. Do you have the VE or swap in a P-pump on that engine?
For the '97, The voltage at the TPS should be 1. 0 volt (+ 0. 2 volts) with the linkage in the idle position. At Wide Open Throttle (WOT), the output voltage of the TPS must be 2. 2-to-2. 9 volts higher than at idle speed. If voltage is not correct, recheck the linkage adjustment.
Recall #B15 - Diesel Engine Throttle Linkage
Or, for the VE-
28. Vehicles equipped with automatic transmission only: Check and adjust the throttle position sensor (TPS) as follows (Figure 27):
* The injection pump throttle lever must be in the low idle position and the throttle lever must reach breakover when the throttle is wide open,
* turn the ignition key to the ON position,
* connect the negative lead of the voltmeter to a good ground (1991 1/2 - 1993 models may use DRB II),
* insert the positive lead of the voltmeter to the center (output) wire of the TPS electrical connector (leave connector attached to TPS),
* with the throttle lever contacting the low idle screw, the TPS output voltage should be 1 volt ± 0. 05 volt,
* adjust the closed throttle TPS setting, if required, by gently rotating the nylon adapter until the correct voltage is obtained,
* open the throttle lever to the wide open position,
* the TPS output voltage should increase a minimum of 2. 25 volts from the closed throttle position voltage.
* if TPS required adjustment, disconnect the battery negative cable for 2 minutes to reset adaptive memory, then reconnect the battery.
Recall #605 Diesel Fuel Injection Pump