Does anyone know what the small black cylinder mounted on the plenum MAP sensor pressure line does? Is it some sort of one-way valve? Just wondering if I should use this on the GM Delco MAP sensor I'm using on the ST215 Caldina side feed I have on the track toy build.
ST205 GT-Four Plenum
ST215 Caldina Plenum - a spare which I sold to Dave Prior for his ST205 JEMS built engine. This has a lot more vacuum ports than the new one I bought from Toyota GB.
Track Toy 'Caldina' Plenum - note there are many fewer vacuum ports than the one above.
Normally I wouldn't worry about the fewer number of vacuum ports but it looks like the black cylinder performs an important function? Current plan is to convert the central M16 temperature sensor port to a 1/8 NPT MAP sensor port