Engine Will Not Start

NOTE: If a tachometer is connected to the tachometer terminal, disconnect it before proceeding with the test.

NOTE: A commercial spark tester may also be used in place of Test Plug.

Check spark at plug using Test Plug (J-26792), while cranking engine. See Fig 2 . If no spark occurs, check another wire. If a few erratic sparks occur, it is considered no spark. If spark occurs, check fuel system and spark plugs.
If no spark occurs, separate 4-terminal EST connector (if computer equipped). If engine starts, check computer memory for trouble codes. If not, check voltage at ignition coil "B+" (battery) terminal while cranking engine. If reading is under 7 volts, repair primary wire circuit.
If reading is 7 volts or more, check "TACH" terminal voltage with ignition on. If reading is less than one volt, replace ignition coil. If reading is from one to 10 volts, replace module and check for spark. If spark occurs, system is okay. If no spark occurs, replace ignition coil.
If reading is more than 10 volts, check for spark at coil output terminal using Test Plug (J-26792) while cranking engine. See Fig 1 . If spark occurs, check cap and rotor for damage.

Fig 1: Testing for Spark at Coil Output Terminal
If no spark occurs, remove pick-up coil connector from module. Turn ignition on. With high input impedance voltmeter, observe voltage at "TACH" terminal while test lamp is momentarily connected to module "P" terminal (BAT.+) (NOT OVER 5 SECONDS). See Fig 3 .
If no drop in voltage occurs, check module ground circuit and for open wires from coil to distributor. If okay, replace module. If voltage drop does occur, check for spark from coil with Test Plug (J-26792) as test lamp is removed from module "P" terminal.
If spark occurs, replace pick-up coil. If no spark occurs, use a module tester and follow instructions. If module tester is not used, check ignition coil ground circuit.
If okay, replace ignition coil and repeat check for spark from coil as outlined in step 6). If spark occurs, system is okay. If no spark occurs, install original coil and replace module.

Fig 2: Modifying Spark Plug for Testing

Fig 3: Distributor Component Testing