1988 F-150, 4.9 straight 6 cyl, 2 w dr, 185,000 miles. I am replacing my valve cover gasket. I found 2 vacuum lines running under the upper intake manifold that appear to have been broken off. They both just stick out from under the protective accordion wrap. I had the fuel rail replaced a year back or so and think it may have happened then. There is a black one and a pink one (vacuum line) and both run around the back of the cover to a " tree" of three valves/switches that mount directly to the valve cover. Where is the broken end supposed to attach too? I can find no tips missing or any other broken ends. There are 3 " plugged" inlets on the vacuum tree that is mounted in the middle of the upper intake manifold.
What do they lead to on the other end? They gotta go somewhere
August, 27, 2006 AT 10:42 AM
" both run around the back of the cover to a " tree" of three valves/switches that mount directly to the valve cover.&Quot; This is where the non broken ends run to.
1988 F-150, 4.9 straight 6 cyl, 2 w dr, 180,000 miles
August, 27, 2006 AT 12:01 PM
Is there a vacuum system diagram on the radiator sight shield? Usually there's other info there also, sparkplug type, gap, etc. If not, you're going to have to get a repair manual, Chilton, whatever to check it out.
August, 27, 2006 AT 12:32 PM
I dont want to sound like I dont appreciate your time to respond to my problem, but I cant find a diagram on the truck or in the book.
All the book says that I have been able to find is that I need to mark all vacumm lines for correct connection when Im putting everything back together.
I think I will try two things.
1. Find someone that has a similar truck in my area, give them a buck to look under the hood, or
2. Hook both lines to the vacuum tree on the upper intake manifold and see if the truck starts and or runs better than it did.
Since I can find no other unused vacuum ports on that side of the engine, Im seriously thinking that they must go to the vacuum tree, and that my buddy couldnt figure out where they broke from so he just put caps on the ports on the tree that didnt have anything going to them.
I would ask him but he has moved out of town with no forewarding address.