Ok, I've compared the two pages (56 & 57) of the 1985 EVTM that deal with the EEC for the 4.9L with the same pages (
56 & 57) of the 1986 EVTM that I have online. And they are essentially the same, so you can use the 1986 pages to plan your removal work.
My experience with a 1982 that had basically the same EEC-III system and feedback carb was that all of the EEC circuitry was stand-alone. In other words, each sensor for the EEC served only the EEC. So I was able to separate the EEC wiring and remove all of it, leaving just the basic wiring.
Similarly, the pages on the
fuel tank selector and gauges are essentially the same for the 4.9L. The only issue is that in '86 the idiot lights had been discontinued but they were offered in '85. So if your friend's truck has idiot lights you need to refer to
Page 56 in the 1981 EVTM.
But if I'm missed something please let me know.
Gary, AKA "Gary fellow":
Profile
Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI