Ignition System Testing

Ignition System

Ignition System Layout:

Ignition System Specifications:

Note: A rough idle or misfire during partial load could be caused by ignition sparks jumping from the plug wire connector to the noise suppression shield, or the cylinder head.
- remove and inspect the plug connector for white spots or burn marks
- on those vehicles equipped with a suppressor shield on the distributor cap, it is necessary to remove the shield and check for white spots or burn marks on the distributor cap

If white spots or burn marks are present, replace the damaged components.

Fig. 1 Rotor, checking





- check that resistance is approximately 1000 ohms

Note: Do not change rotor when installing radio; rotor must be marked with R1.

Fig. 2 ignition wires, checking





- check wires between distributor and spark plugs (including connectors) for continuity
resistance should not vary greatly between wires

- check wire between ignition coil and distributor, (including connectors)
resistance should not be greater than 12000 ohms

Fig. 3 Distributor drive, removing






Fig. 4 Distributor drive, installing






- set crankshaft to TDC on cylinder No.1
- install drive shaft so that offset slot is at an angle about 12° to engine centerline (smaller segment toward coil side)
- install spacer spring

CAUTION: When working on vehicles with Hall ignition system, observe following precautions to prevent injury or damage to ignition system:
- do not touch or remove high tension wire when running or cranking engine
- disconnect ignition wires only when ignition is switched off
- test instruments should be connected/disconnected only when ignition is switched off
- do not connect any condenser to terminal 1
- do not tow cars without disconnecting plugs on ignition control unit
- do not crank engine until high tension wire of distributor cap (terminal 4) is connected to ground with jumper wire (example: compression check, etc.)
- do not leave battery connected when electric welding on car
- do not substitute rotor of ignition distributor with one of different type
- when installing suppressor, use only 1000 ohms for high tension wires and 1000 to 5000 ohms for spark plug connectors
- do not wash engine when it is running
- do not use battery booster longer than 1 minute nor exceed 16.5 volts with booster

Ignition coil secondary resistance, checking






- disconnect all wires from coil terminals
- measure resistance between negative terminal 1 and coil high tension terminal 4
resistance: 2400 - 3500 ohms

- if not within tolerance, replace ignition coil

Ignition coil primary resistance, checking






- disconnect all wires from coil terminals
- measure resistance between positive 15 and negative 1 coil terminals
resistance:0.52 - 0.76 ohms

- if not within tolerance, replace ignition coil

Fig. 6 Ignition distributor, installing






- set crankshaft to TDC on cylinder No.1
- turn rotor until it is pointing to No.1 cylinder mark on edge of housing
- install distributor
- clean distributor cap, check for cracks, signs of tracking and rotor tightness on shaft
- adjust ignition timing