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goodwrench9124, ASE Certified Technician
Category: Chevy
Satisfied Customers: 3432
Experience:  Ase Master Certified, GM Master Certified Tech. Awarded GM Top performer, Hybrid certified
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Which of the two timing marks I have to follow to set the ...

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Which of the two timing marks I have to follow to set the timing right on a chevy blazer 4.3L vortec engine?
Hello, and welcome to JA!! what year do you have??
Customer: replied 9 years ago.



WARNING: To prevent possible personal injury from a moving vehicle or operating engine do the following before performing the checks:

  • Engage the parking brake and block the wheels.
  • Place the transmission is neutral .

  1. Refer to the important engine information label located in the engine compartment on the label.
  2. Put the Ignition Control (IC) system in the bypass mode by disconnecting the "set timing" connector. This is a single wire sealed connector that has a tan with black stripe lead. The location of the "set timing" connector with a Powertrain Control Module (PCM) controller is near the PCM connectors in the passenger compartment.
  3. With the ignition switch "OFF," connect the pickup lead of the timing light to the number one spark plug. Use a jumper lead between the wire and plug or an inductive type pickup. NOTE : DO NOT pierce the wire or attempt to insert a wire between the boot and the wire. Connect the timing light power leads according to manufacturer's instructions.
  4. Start the engine, and aim the timing light at the timing mark. The line on the balancer or pulley will line up at the timing mark. The timing specification is 0°BTDC. If a change is necessary, loosen the distributor hold-down clamp bolt at the base of the distributor. While observing the mark with the timing light, slightly rotate the distributor until the line indicates the correct timing. Tighten the hold-down bolt, and recheck the timing.
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Customer: replied 9 years ago.
I've a EDI system and also I've removed the distribuitor and moved the crankshaft off position.I know how to set it back by hand but don't know on what mark has to be set.

ok, is this the dist you have???


Customer: replied 9 years ago.

ok, sorry about that, here is the info you need!!!!

Distributor Installation

    Object Number: 334551  Size: SH

    Important: The engine front cover has 2 alignment tabs and the crankshaft balancer has 2 alignment marks (spaced 90 degrees apart) which are used for positioning number 1 piston at top dead center (TDC). With the piston on the compression stroke and at top dead center, the crankshaft balancer alignment mark (1) must align with the engine front cover tab (2) and the crankshaft balancer alignment mark (4) must align with the engine front cover tab (3).

  1. Rotate the crankshaft balancer clockwise until the alignment marks on the crankshaft balancer are aligned with the tabs on the engine front cover and the number 1 piston is at top dead center of the compression stroke.
    Object Number: 301393  Size: SH

  2. Remove the distributor cap bolts and discard.
  3. Remove the distributor cap.
    Object Number: 43756  Size: SH

  4. Install a NEW distributor gasket onto the distributor.
  5. Align the indent hole on the driven gear with the paint mark on the distributor housing.
    Object Number: 68505  Size: SH

  6. Ensure that the distributor rotor segment points to the cap hold area.
  7. Align the slotted tang in the oil pump driveshaft with the distributor driveshaft.

    Rotate the oil pump driveshaft with a screwdriver if necessary.

    Object Number: 310298  Size: SH

  8. Install the distributor and distributor clamp.

    The flat in the distributor housing must point toward the front of the engine.

    Object Number: 334555  Size: SH

  9. Once the distributor is fully seated, align the distributor rotor segment with the number 6 pointer (1) that is cast into the distributor base.

    If the distributor rotor segment does not come within a few degrees of the number 6 pointer (1), the gear mesh between the distributor and camshaft may be off a tooth or more. Repeat the procedure again in order to achieve proper alignment.

    Object Number: 34403  Size: SH

  10. Install the distributor clamp bolt.

    Tighten the distributor clamp bolt to 25 N·m (18 lb ft).

    Object Number: 301393  Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  11. Install the distributor cap and NEW distributor cap bolts.

    Tighten the distributor cap bolts to 2.4 N·m (21 lb in).

    Object Number: 387772  Size: SH

  12. Install the ignition coil wire harness.