Just as a side note, I came across this TSB that I thought that I should bring to your attention.
Engine/Ignition - No Start Condition
NO START - EEC IV - "E" COIL
Article No. 87-20-18FORD: 1983-86 LTD 1983-87 ESCORT, EXP, MUSTANG, THUNDERBIRD, CROWN VICTORIA 1984-87 TEMPO 1986-87 TAURUS
LINCOLN-MERCURY: 1983 LN7
1983-86 MARQUIS 1983-87 LYNX, COUGAR, GRAND MARQUIS, MARK VII, CONTINENTAL, LINCOLN TOWN CAR
1984-87 TOPAZ 1986-87 SABLE
LIGHT TRUCK: 1983-87 RANGER, E-SERIES, F-SERIES, BRONCO 1984-87 BRONCO II 1986-87 AEROSTAR
This article is being republished in its entirety to expand the model year coverage.
ISSUE: The primary winding of the E-core ignition coil may be damaged if the wire harness containing the tachometer circuit has a short to ground.
ACTION: Before replacing the E-core ignition coil, perform the following diagnostic procedure.
1. Turn ignition to "ON" position.
2. Measure and record battery voltage.
3. Measure and record voltage between negative terminal and coil and battery ground post as shown, Figure 50.
4. If the differencce in readings is greater than 1.0 volt, check tachometer circuit for a potential short to ground.
5. If a short is present, make necessary wire harness repair.
6. Replace ignition coil as required.
OTHER APPLICABLE ARTICLES: Supersedes 84-14-18, 84-14-18-S, 85-16-13, 86-2-21
WARRANTY STATUS: "INFORMATION ONLY"