Mercury E8TZ-12029-A Coil Assembly - Ignition

You can Select Your Vehicle to check if E8TZ-12029-A fits your vehicle.

Turn off ignition, disconnect battery, detach wiring harness from ignition coil. Check terminals for dirt, corrosion, damage. Use ohmmeter to measure resistance between terminals: 2.3L engines B+ to Coil 1, B+ to Coil 2 or 3, B+ to Coil 4. 4.DL engines B+ to Coil 1, 2, 3. Resistance should be 0.3-1.0 ohms. If not, replace coil. Measure resistance between coil terminals and spark plug wire towers. If 6,500-11,500 ohms, coils are OK. If not, replace coil pack. On 2.3L engines, if one pack is bad, other doesn't need replacing. 4.0L engine has one pack with three coils. Disconnect battery, unplug harness from coil pack. Remove spark plug wires, screws, and coil pack. Install new pack, tighten screws. Apply dielectric compound to spark plug boots. Attach wires and battery.

To check the secondary wire and the ignition coil, begin by disconnecting the ignition coil connector and checking for dirt, corrosion, or damage. Use an already-known good coil and a spark tester to test for sparks. If a spark is present, measure the resistance in the ignition coil wire. Replace it if its resistance is over 7000 ohms per foot, if within specification, replace the ignition coil. To check for voltage supplied to the ignition coil, remove the coil connector and take readings at positive terminal of the ignition coil. If it is more than 90% of battery voltage, check through the ignition coil connector and terminals; otherwise, examine wiring or ign. switch. For measuring the primary resistance of the ignition coil with an ohmmeter, connect between positive and negative terminals of the coil. If this reading is between 0.3-1.0 ohms, then there is no problem with your ignition coils hence proceed to secondary resistance test, otherwise replace your ignition coils.