Part 2 of 2
Chart C-4M Part 2 Of 2:
Chart C-4M Wiring Diagram:
CIRCUIT DESCRIPTION:
The "Integrated Direct Ignition" system (IDI) uses a waste spark method of distribution. In this type of system the ignition module triggers the # 1-4 coil pair resulting in both # 1 and # 4 spark plugs firing at the same time. # 1 cylinder is on the compression stroke at the same time # 4 is on the exhaust stroke, resulting in a lower energy requirement to fire # 4 spark plug. This leaves the remainder of the high voltage to be used to fire # 1 spark plug. On this application, the crank sensor is mounted to, and protrudes through the block to within approximately 0.050" of the crankshaft reluctor. Since the reluctor is a machined portion of the crankshaft and the sensor is mounted in a fixed position on the block, timing adjustments are not possible or necessary.
TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart.
6. This checks for a grounded or low resistance injector. This condition will not able the paired injector to properly deliver fuel.
7. Checks for injector driver circuit.
DIAGNOSTIC AIDS:
Verify IDI connector terminal "K", CKT 450 resistance to ground is less than 0.5 ohm. A shorted or low resistance injector may cause a miss in the other injector in that pair. (1&4 or 2&3).