How 2 detect vaccum leaks

Anyone ever trouibleshoot a possible vaccum leak on thier SC 's ? I tried to locate some possible leaks, but didnt see much of any vaccum lines (lemme guess ford put them under the car)

Virtually all your vacuum lines run in behind the supercharger(it figures huh). The main source is taken from the inlet plenum and then it branches off all over the place. If you remove your wiper arms and the cowl you will gain somewhat easier access to the vacuum lines. Over on the far left side up in the corner near the brake unit is a splitter tree that many vacuum lines source from. There are several small lines that run from there and they are very susceptible to cracking or severing or leaking at the rubber nipple that joins it to a vacuum source. Also about midway along the cowl, under it I should say is another splitter tree for vacuum

leak

les, thanks for the info. im having a problem with idle and im trying to locate the source.

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IF i have a vaccum leak, would that present any service codes ?

Take your blower belt off and start the car. Use your favorite method of leak-checking such as carb cleaner or starter fluid on all connections including the intercooler fittings.

'bird

ps: thought this up a few weeks ago, let me know if it works...

Hi, guys. I'm glad I saw this thread. Les, thank you for sharing the locations of the vacuum hoses and source trees. I have learned over the years from the mustangs I have bought that vacuum lines can be an elusive source of idling problems. (Love the 69 cougars ). Now with many vacuum lines being of plastic, it's even doubly important to make sure the lines are in good shape. My idle too has been just barely irratic enough lately to make me want to get in there and check them. I highly recommend checking all of the lines, especially if you are planning on keeping the car for a while. I still have to remind myself how old my 35th is. The looks of these mn12 birds will always be timeless to me. Have a great week all.

Because of age etc, the elbow that hooks to the PCV valve on the passenger valve cover is prone to cracking. It has an extremely thin wall and can split where it connects on top of the valve.

'bird

Propane works well, just spray some around all the vacuum fittings and when the idle goes up, you found it.

thanks you all problem solved

I had the car diag'd and the IAC valve is bad.