Failure To Start Test

NOTE: Perform "Ignition System Starting Test " first. Failure to do so may result in lost diagnostic time or incorrect test results.

Measure and record battery voltage. Measure specific gravity, which must be at least 1.220 (temperature corrected) to deliver proper voltage.
Turn ignition switch "OFF", and disconnect 10-wire connector from spark control computer. Repeat Ignition System Starting Test, step 1). If spark results, replace spark control computer.
If no spark is obtained, check voltage at coil positive terminal. With ignition switch "ON", connect positive voltmeter lead to coil positive terminal and negative lead to a good ground. Reading should be within 1 volt of battery voltage. If not, check wiring between battery and coil positive terminal.
If voltage at positive coil terminal was correct, connect positive voltmeter lead to coil negative terminal and negative lead to a good ground. Again, voltage should be within 1 volt of battery voltage. If not, replace ignition coil.
NOTE: You may wish to check coil primary and secondary resistance before replacing ignition coil. However, if you have battery voltage on positive side, but not on negative side of coil, ignition coil normally requires replacement.
If voltage was correct at negative coil terminal, but no spark resulted in Ignition System Starting Test, step 1), replace ignition coil.
If spark results, but engine will not start, turn ignition switch to the "RUN" position. Connect positive voltmeter lead to terminal 1 of 10-wire connector and negative lead to a good ground. See Fig 1. Reading should be within 1 volt of battery voltage. If not, check wire for open and repair it, repeating this step 6) once more. Reconnect 10-wire connector to computer.

Fig 1: Voltmeter Hookup for Checking Terminal 1 Voltage
Courtesy of CHRYSLER GROUP, LLC
If battery voltage was recorded in step 6), place a thin insulator (piece of paper) between curb idle adjusting screw and carburetor switch or make sure screw does not touch switch. See Fig 2. Connect negative lead of voltmeter to a good ground. Turn ignition switch to "RUN" position, and touch positive voltmeter lead to carburetor switch terminal. Reading should be approximately 5 volts. If so, proceed to step 10).

Fig 2: Checking Voltage at Carburetor Switch
Courtesy of CHRYSLER GROUP, LLC
If voltage was not at least 5 volts, turn ignition switch "OFF". Disconnect 10-wire connector from computer. Turn ignition switch back to "RUN" position. Connect positive voltmeter lead to terminal 2 of 10-wire connector and negative lead to ground. See Fig 3. Voltage reading should again be within 1 volt of battery voltage. If not correct, check wiring between terminal 2 and ignition switch for opens, shorts or poor connections.

Fig 3: Voltmeter Hookup for Checking Terminal 2 Voltage
Courtesy of CHRYSLER GROUP, LLC
If voltage at terminal 2 was correct, turn ignition switch "OFF". Using an ohmmeter, check continuity between terminal 7 of 10-wire connector and carburetor switch terminal. See Fig 4. Continuity should exist. If not, check wire between connections for opens, shorts or poor connections. If continuity is present, use an ohmmeter with leads attached to terminal 10 and engine ground to check continuity of ground circuit. See Fig 5. If there is continuity, replace computer. If there is no continuity, check wire from terminal 10 to ground. If engine fails to start, proceed to next step.

Fig 4: Ohmmeter Hookup for Checking Carburetor Switch Wiring Harness
Courtesy of CHRYSLER GROUP, LLC

Fig 5: Ohmmeter Hookup for Checking Computer Ground Circuit
Courtesy of CHRYSLER GROUP, LLC
Turn ignition switch "OFF". Attach ohmmeter leads to terminals 5 and 9 of 10-wire harness connector to check run pickup coil resistance and to terminals 3 and 9 to check start pickup coil resistance. See Fig 6. Resistance should be 150-900 ohms. If so, proceed to step 12).

Fig 6: Ohmmeter Hookup for Checking Pick-Up Coil Resistance
Courtesy of CHRYSLER GROUP, LLC
If not, disconnect distributor connectors, and attach ohmmeter leads to run pick-up coil leads and then to start pickup coil leads coming from distributor. If resistance is now okay, wiring harness is defective. If resistance is still not 150-900 ohms, replace pick-up coils, as necessary.
Next, connect one lead of an ohmmeter to engine ground and touch other lead to each terminal of leads coming from 2 distributor pick-up coils. There should be no continuity. If continuity is indicated, replace pick-up coil.
Remove distributor cap and check each reluctor-to-pick-up coil air gap for 0.006" clearance. If not to specification, adjust gap, using a non-magnetic feeler gauge. See Fig 7.

Fig 7: Checking Distributor Pick-Up Air Gap
Courtesy of CHRYSLER GROUP, LLC

NOTE: To adjust gap, loosen pick-up coil hold-down screws, move pick-up coil against feeler gauge resting against reluctor tooth. Tighten hold-down screw, remove feeler gauge, and recheck gap.
Install distributor cap and reinstall all wiring. If engine fails to start, replace spark control computer. If it still fails to start, install original computer and retest.