The resistor is matched to the pump's calibration, so unless the rebuilder was thoughtful enough to stamp the resistor number on the pump somewhere you're kind of SOL if the resistor is missing.
The pump can be forced into relearn mode, KOEO, accel pedal to the floor for 45 seconds and engine temp over 170 or 175 degrees, I dont remember, then, key off for 30 seconds, then, start the engine, engine will run very rough and even to the point of dying, it is relearning timing too, restart the engine if it dies and then it will proceed through the learning curve and idle at a normal rate. It too will relearn after 50 key cycles, from what I have been told by those with much more experience in such matters. LOL
Scared the crap out of Me the first time I run through the relearn process, after installing new timing chain/sprocket components. Engine started running rough and died and I thought, oh S#*t. LOL