Does anyone have a vacuum diagram for a 71 six? Have the shop manuals but no clear diagram for vacuum routing. Starting from scratch. Also there is a 3 port fitting on the manifold that I need to replace. Any suggestions on where that may be found?
Hello, I hope this helps. (Alot of Diagrams below) * It might help if you post whether you have a 200 or 250 engine, and whether your transmission is auto or manual...and I am assuming you are talking about a 71' Maverick or Comet. ...so I apologize if I have the wrong diagrams for your car: Also...I am not sure if your setup has the Ported Vacuum Switch valve (PVS), or distributor vacuum control valve... also sometimes called a coolant temperature sensing valve. ...so I'm not sure by "3 port fitting" if you mean these PVS valves: or this: or this: But here are some various Vacuum Diagrams for the 71' Maverick 6 cyl: (Diagrams courtesy of Jeff's extremely helpful website): Vacuum Feed to the Heater and Air Conditioning Controls:
Vacuums diagram Sorry! You are correct I need to provide more info. The 71 has a 250 six with AC. The vacuumed tree does not appear to be a valve just a distribution tree in the intake. Problem is 2 of the three nipples have broken off. Also they appear to be 3 different sizes. I assume the largest goes to the tranny? I really cannot locate a coherent diagram. Does not have a dual diaphragm distributer. Thank You!
Unless you need it all for emissions it'll run fine with the dist connected to ported vac on the carb and the trans modulator to manifold vac... If you have A/C controls then that should also connect to manifold vac... Also there should be a vac reverse canister in the A/C hookup but that only to keep it from changing functions at WOT, climbing hills or other low vac conditions... In A/C sustems the heater control valve is operated by vac from the controls on dash...
And if you're wanting to replace your broken "vacuum manifold distribution tree", and if the new ones are too expensive, I would just grab one from a junk yard. Mansfield Mustang has several new variations on these fittings: http://mansfieldmustang.com/EnginePCV.html the NPD one pictured above is pricey, and located here: http://www.npdlink.com/store/products/fitting_vacuum_port_front-175803-0.html And here is what the original Factory setup, should have been for your engine: 1971 (250 I6 with A/C) Man. Trans: Vacuum Schematic Diagram #3 pictured above. Auto Trans: Vacuum Schematic Diagram #4 or #5 pictured above (Look and see if you have a PVS Valve on your setup) ...And...like Tom said above...if you only have a single port on your distributor vacuum advance, then it should lead back to the carb. Here is a page that shows single ones for the year of 73, but again, there are so many variations. It sounds like your original setup has all changed: http://1bad6t.com/Maverick/repair/73Vac_wAC.html * And a line should go to the tranny...here is are some pictures showing where it connects on the tranny end. Sorry for the large photo...just follow the line in the picture:
