If you believe your FAV may not be performing properly, here are a few steps to determine what the issue may be.
First you must determine if you may have an electrical or mechanical issue.
Electrical issues may be:
A) A bad FAV cable, broken wires or a loose connection, etc.
B) A blown transistor on the controller
C) The system not telling the FAV to open
A) Contaminated methanol has swollen the FAV shut.
For the electrical issues listed, for each item check the following:
For A, use a OHM meter and check the cable end to end You should have continuity from all 4 pins to the plug. Only the two parallel connections are used on the plug, two pins go to one blade connection, two pins to the other.
For B, this would be determined by contacting the factory, but all other options must be exhausted first. This usually happens by user error, i.e., getting water in the FAV plug causing a dead short across the parallel blade connections.
For C, When the system is put in test, with the PRK jumper to SYS, the yellow THRES LED inside the controller should be on as well as the pump running. At this time the FAV should be open as passing fluid.
To test for a mechanical issue:
For D, remove the FAV cable from the FAV. Put the system in test so the pump is running. Put 12v across the to parallel blades of the FAV coil. It should click and hold open and pass fluid, if it does not, it has been damaged by contaminated fluid. Read more on methanol contamination here.