just bought a 1992 190e 2.3 and the fuel pressure regulator vacuum hose was missing. got a hose for it and attached it to the small T-fitting coming out from the hose that connects the idle air control valve to the air cleaner and valve cover. problem is that there is no vacuum. don't have a book for this car and it's the first benz i've ever worked on (owned) so not even sure if this is where the FPR vacuum hose needs to go. any help will be appreciated.