2001 5.4 issues

[james kyser]

Hello everyone I'm new to ford expeditions and need some help. I recently acquired a 2001 eddie bauer 4wd 5.4 less than 150k miles . it is in excellent shape but has been sitting up for a year or so. It had a terrible miss the guy couldn't find so I took it home to figure out. Turns out it had water in the rear 2 sparkplug tubes which I learned is very common. Now it is runs a lot better but still has a minor miss and seems low on power. It gives a vacuum leak code but I cannot find the leak anywhere. It seems to have an odd electrical issue the 4x4 and abs lights randomly flash and the blinkers stop working. seems to happy at the same time. And last issue is the ac it randomly gets warm while going down interstate. my thought is the vacuum leak is causing the air diverters to half way open between heat and cold. any tips or ideas will be greatly appreciated

 

[Bain64]

Yes the vacuum leak can cause most of what you mention. Start looking at the brake booster and follow the vacuum lines. Does this diagram help?
Also, you'll likely get more responses in the 1st gen forum. You may be correct to post here in the Engine section, but the 1st gen section gets much more 'traffic'.
http://www.2carpros.com/forum/automotive_pictures/249564_Graphic_200.jpg

Edit: The vacuum reservoir is under the battery, trace the lines coming off of it. Also, check your PCV and IAC. Inspect all hoses, feel every inch of the hose in places you cannot directly see.