I have a 93 CAN Miata, which originally had a 1.6 engine and got a 1.8 NA BP engine a few years ago. This was done and registered by the previous owner. The engine runs well, has a good cold start and drives and pulls well. What I am looking for in this thread is actually the warm start, or a line in the engine room, which in my opinion is the Pr If I drive with the original air filter box (currently open filter), a hose (see pictures) is inserted into the air filter box after air filter (directly above the air filter plate). I tracked the line once, it comes from the passenger side and starts from a metal pipe. In addition, it smells like sprite more often when the car is standing after the ride. If I then want to start, it will drain without gas. Therefore, my guess that it has a fuel vent The point is that the problem with the bad start does not occur when I drive the open filter. The line is then open in the engine compartment directly from the open filter fixed, so that an almost same system prevails, like me original box. Maybe you have an idea or can tell me whether this hose goes into the air filter box with you or not and what it can be Thank you in advance, excuse the long text. Have a nice evening!