Where is the knock sensor located on a EEC IV 1987 F150 EFI 5.0 code N engine? I have asked 3 Ford dealers and got 3 different locations. They were consistant in that they gave the part number E3AZ-12A699A.

 

If it has one it's on the back of the block at the top right behind the intake.

 

It should have one, see picture, looking at the back of the engine:

 

Eric, mighty glad you showed that picture, the only thing i could see was the vacuum thingy under the arrowhead. I will get a ladder and mirror tomorrow to see if i can get my 26 inch legs and 46 inch waist where i can see. which brings up another something I just learned a month ago. you can change the pcv valve without taking that intake contraption off. thats when i remembered why I had 3 new pcv valves on the shelf. each time i did a tune up i bought a pcv valve and being rather short and some what squat couldnt figure why ford went brain dead and put a 2 1/2 inch long valve in a 1 1/2 gap. I wasnt about to pull an intake for a pcv valve. so at some point later on when i needed valve cover gaskets which was about as often as tune ups, i just took it to the dealer and said put in new pcv valve when you fix the leaking covers. Something about not admitting i didnt know how to change a pcv valve.