Distributors put the spark in spark plug. The spinning rotor inside the distributor transmits electricity from the ignition coil down the spark plug wires and into the cylinders where the plugs release it, igniting the combustion process. The right amount of spark and the timing are the responsibility of the distributor. Correct installation of your 1997 Blazer's distributor will insure your Vortec 4300 V-6 delivers it's 190 horses.
Items you will need
- Grease pencil
- 10 mm distributor wrench
- Socket set
- Torx bit
- Bit driver
- Foot-pound torque wrench
- Inch-pound torque wrench
- Breaker bar
- Long flat-head screwdriver
- Wood dowel
Identify the location of the spark plug wires with tape and remove the wires from the distributor. Unplug the ignition coil wire from the distributor and the ignition module connector at the base of the distributor.
Remove the two cap screws using a Torx bit and remove the distributor cap. Mark the location of the rotor in relation to the distributor base using a grease pencil. Mark the location of the distributor's base in relation to the engine.
Remove the distributor clamp bolt using the 10 mm distributor wrench. The clamp is located on the passenger side of the distributor hole. Remove the clamp and lift the distributor straight up. Note how the rotor moves approximately 42 degrees as the gear disengages. Mark this second location with the grease pencil. Remove the old distributor gasket and discard it.
Installation With MatchmarksStep 1
Transfer pencil marks to the new distributor base. Attach the rotor to the distributor with two screws using a Torx bit and driver. Align the rotor with the second location mark.
Install a new gasket onto the distributor shaft and insert the distributor into the engine until it's seated. Confirm that the rotor has aligned with the pencil mark on the distributor body. If the rotor does not align with the mark, you may have missed the gear by a tooth. Remove the distributor and install it again. Reinstall the distributor clamp and bolt. Torque the bolt to 18 foot-pounds.
Install the distributor cap and screws using a Torx bit. Torque the cap screws to 21 inch-pounds. Reconnect the ignition module wires at the base of the distributor and reinstall the spark plug wires. Reconnect the ignition coil wire.
Installation Without MatchmarksStep 1
Disconnect the negative battery cable. Remove the spark plugs using a ratchet and socket.
Locate the forward cylinder on the driver side of the engine. Place your thumb over the spark plug hole while an assistant rotates the crankshaft pulley clockwise using a breaker bar and socket. During the compression stroke the piston will compress air out the hole and your thumb will be forced out of position. Place a wooden dowel or pencil into the spark plug hole and onto the piston, and resume turning the engine until the dowel reaches it's highest point. Align the notched lines in the harmonic balancer with the V-shaped notches on the front of the engine. This is top dead center of the compression stroke.
Slide the distributor gasket onto the distributor's driveshaft. The distributor will mate with the oil pump driveshaft when seated. Align the oil pump drive at the bottom of the distributor hole using a long flat-head screwdriver. Insert the distributor into the engine. Confirm that the rotor is aligned with the "6" pointer stamped into the distributor base. Align the plug wire towers perpendicular to the engine centerline.
Reinstall the clamp bolt and torque it to 18 foot-pounds. Install the distributor cap and secure the bolts with a Torx bit. Torque the cap bolts to 21 inch-pounds. Reinstall the spark plugs and wires. Reconnect the ignition coil and ignition module. Connect the negative battery cable.
- Cover the distributor hole with a clean rag to prevent dirt or tools from falling into the engine.
- Watch for moving components such as belts and pulleys when turning the engine. Rotating an engine by hand can start the engine if the battery is not disconnected and the spark plugs have not been removed.
- Mellon, Thomas (Ed.). (1999). Chilton General Motors S-Series Pick-Ups & SUVs 1994-99 Repair Manual. West Chester PA: Chilton Nichols
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