Service Manual, F-10, upper right corner of the Vacuum Hose Routing Diagram; Pressure solenoid has a vac line coming off with a "gas filter". Is this just a check valve or something special? Arrow shows it is a one-way on the filter...but it is open both ways.

Question: Would one of Dale Clark's VITON check valves work in this application?

Mil grasias,

 

are you talking about the MAP sensor on the driver's side firewall? that is not a check valve but a filter. keeps oil particles etc from getting to the sensor.

 

That is probably it. It is the small (box of matches size) black sensor mounted to the firewall. Now that I study it, a filter would make sense. I was whipped after tearing everything off the engine and had check valve on the brain. Thinking about it, filters have directional arrows too.

But just to make sure...is it just a filter (air moves through both ends) or is it supposed to have a "one way" valve type feature also? I do not see a "test" for it in the manual, so I could assume it is just a filter...but I hate assuming anything.

 

It's a filter. It flows both ways but has a "filtration direction".

 

Doesn't matter which way it goes but most cars I see have the arrow facing the intake manifold. The map sensor will eventually go bad without it.

 

Exactly. The arrow is there so that the dirty and clean side of the filter don't get switched.