Timing the Model A engine
As the spark must occur at the end of the compression stroke, with the piston approaching top dead center (TDC), the timing must be checked from that point. To find the compression stroke and time the spark, proceed with the following steps:
- Fully retard the spark lever on the steering column; that is, push all the way up.
- Using a standard feeler gauge, check for 0.018" to 0.022" gap between breaker contact points.
- Remove cap screw, which has timing pin attached to its head, located on front side of timing gear cover and insert the pin into the opening.
- With the starting crank, turn the engine over slowly while pressing in firmly on the pin. When piston No. 1 reaches the end of the compression stroke, the timing pin will slip into a small recess in the camshaft gear.
- With the pin now resting in this recess, remove distributor cover, lift off the rotor and distributor body.
- Loosen cam locking screw until cam can be turned.
- Replace rotor and turn it until rotor arm is opposite No. 1 contact point in distributor head.
 Timing the ignition
To Time the Ignition,first retard spark on steering column, then remove distributor cover, rotor and body shown above.
Next, set points using screwdriver and feeler gauge to between 0.018" and 0.022".
Then the timing Pin is inserted through hole on front side of timing gear cover and engine turned by crank until pin falls into recess on face of gear.
Loosen cam locking screw (above), then replace rotor and distributor body. Turn rotor until arm is opposite No. 1 contact point. Remove rotor and body, then turn cam clockwise until breaker points just close, then retighten cam locking screw.
Breaker cam can be rocked with fingers to set ignition timing. Before checking timing with switch on, be sure to remove timing pin from hole on gear cover.
Withdraw rotor from cam and slightly turn the cam in a clockwise direction until the breaker points just close. Then tighten the cam locking screw securely to prevent backlash in the distributor shaft from affecting the timing.
Now check the timing by withdrawing the timing pin from the recess in the timing gear, turn on the ignition switch, then again insert the timing pin into the timing gear cover. Turn the engine with the crank while pressing in on the timing pin. If properly timed, a spark should occur between the breaker points just as the pin falls into the timing gear recess. If a spark does not occur, some error has been made and it will be necessary to retrace your work until the spark appears.
Withdraw timing pin, turn it around, and turn cap screw back tightly into timing gear cover. Replace rotor and distributor cover.
 Tracing Ignition Trouble
Should ignition trouble develop, first check the battery connections. Also check the wire from the terminal box to the starting motor and the wire from the terminal box to the coil and the wire from the coil to the switch.
If these connections and wires are good, then check the switch as follows:
- Remove the four screws which hold the instrument panel in place and pull the panel back. *Disconnect the wire on the lock case.
- The switch may then be tested in the following manner by using a six-volt power source and a test lamp.
- First Test: With the breaker points in the distributor open, place one test probe on the primary terminal inside the distributor and the other test probe on the switch terminal. With the switch unlocked, the test lamp should light. With the switch locked the lamp should not light.
- Second test: Place one test probe on the primary terminal inside the distributor as in the first test and the other test probe on the switch casing. With the switch locked as described in the first test or if the lamp lights with the switch unlocked in the second test, there is either a ground in the switch or the distributor condenser is shorted or grounded and it will be necessary to disconnect the condenser from the distributor to determine whether the trouble is in the switch or condenser.
- Use a new condenser and again try the second test. Should the lamp still burn when the switch is in the unlocked position, the trouble lies in the switch and it must be checked.
Other easy checks can be made on the ignition system as follows:
- Remove the high tension wire from the distributor. With the key on, turn over the engine. With the lead held close to the block, a spark should occur. If not, the problem is in the coil or the wiring to the coil.
- Remove the cover and cap of the distributor. With the key on, place a screwdriver between the points. If a spark occurs, fine, but if not, you have problems with the condenser or ignition wires leading to the distributor.
- Remove a spark plug strap at the plug. Look closely for spark from the distributor to the plug. If there is no spark, the problem is from the distributor back.
- Remove the ignition cable from the distributor. (This may be difficult if you have a hold-down clamp on the armored cable to the head of the engine.) Turn on the key, then rub the button on the end of the cable on a head bolt. A spark should occur. If not, you have trouble with the ignition switch.