How to make sure that your WUR is faulty?
The only way to test your warm up regulator is measuring the control pressure. If the engine is cold, the control pressure has to be low, around 0,5-1,5 bar. (You can find the accurate values in repair manual for your car). But with warm engine the control pressure has to rise to around 3,5-4 bar. If you can not observe correct values, although the fuel system supply pressure is correct, your WUR definitely needs a fix.
If you don't find your WUR number on our list, your WUR has an additional vacuum diaphragm, and because there is no good quality spare part available, we do not offer mending the vacuum diaphragms. You can test your additional diaphragms by vacuum testing the cells. It is quite easy: connect a manual vacuum pump to the WUR small air connector, and apply vacuum. WUR has to keep vacuum readings. In this case you can send your WUR to our address below. But if the WUR does not keep vacuum, the diaphragm is broken, so we will not be able to repair the WUR completely.