Firing Order 4.3 Vortec [Explanation of Diagram]

General Motors first debuted its series of six-cylinder, small-block gas engines known as the Chevy 4.3L Vortec in 1985. The company plans to stop producing these engines entirely by 2024. The Chevrolet 4.3-liter Vortec has been the most successful member of the Vortec engine family throughout its history.

Even though the Chevy 4.3L Vortec engine has been in operation for four decades, its basic structure has stayed the same during that time. However, there have been a number of modifications, alterations, and additions made to its elements and capabilities.

Firing order of 4.3 Vortec

  • The Firing Order for 4.3 Vortec Engine is 1-6-5-4-3-2

Explanation of 4.3 Vortec firing order

The 4.3 Vortec firing order is 1-6-5-4-3-2 and this has a clockwise rotation. Being a V6 engine it has 6 cylinders thus a firing order of a number of sequences 6. First Cylinder Number 1 is on the driver’s side, ahead of Cylinder Number 2. Next up are numbers 3 and 5.

Passenger side is #2, #4, #6. The first cylinder on the distributor cap may be found on the top side of the cap. The firing sequence is determined by moving clockwise around the distributor. The 4.3 TBI firing order is also the same as above.

For a long number of years, this firing order has been unchanged. So, 1994 4.3 Vortec firing order, 1995 4.3 Vortec firing order, 2002 4.3 Vortec firing order, and 2004 4.3 Vortec firing order are all the same.

This Firing order applies to 

  • Chevy 4.3
  • Chevy 3.3
  • Chevy 3.8

Torque Specifications

Timing Cover Torque spec 10 ft-lbs
Camshaft Timing Sprocket Torque Specs 21 ft-lbs
Camshaft Retaining Plate Bolts Torque spec 8 ft-lbs
Crankshaft Postition Sensor Torque spec 10 ft-lbs
Cylinder Head Torque Specs (Shortest) 22 ft-lbs + 55°
Cylinder Head Torque Specs (Medium) 22 ft-lbs + 65°
Cylinder Head Torque Specs (Longest) 22 ft-lbs + 75°
Rocker Arm Torque specs 20 ft-lbs
Valve Lifter Retainer Torque specs 12 ft-lbs
Valve Cover Torque specs 8 ft-lbs
Exhaust Manifold Torque specs 25 ft-lbs
Exhaust Manifold to Pipe Torque 20 ft-lbs
Main Cap Bolts Torque Spec 15 ft-lbs + 75°
Connecting Rod Bolts Torque Spec 20 ft-lbs + 70°
Oil Pump Bolt Torque Spec 65 ft-lbs
Oil Pan Torque Specs 15 ft-lbs
Oil Pan Drain Plug Torques 15 ft-lbs
Intake Manifold 15 ft-lbs
Fuel Rail Torque Specs 8 ft-lbs
Spark Plugs Torque Specs 11 ft-lbs
Throttle Body Torque Specs 12 ft-lbs
Distributor Holder Bolt Torque Spec 15 ft-lbs

Check 16 Cylinder Engine Firing Order

Firing order for similar vehicle

  1. GM 3800  1-6-5-4-3-2
  2. Rover KV6  1-6-5-4-3-2

What is the relation between firing order and distributor rotation in 4.3 Vortec?

4.3 Vortec firing order and distributor rotation will be discussed here. The manner in which the ignition leads of an engine are lit by the ignition system is referred to as the firing order of the engine.

If an engine has a distributor, the route that the ignition coil wire takes from the distributor cap to the ignition systems for each cylinder is what determines the firing sequence of the cylinders in the engine. The trail starts at the distributor cap. During the compression stage, the distributor rotor should line with the number one ignition system wire in the distributor cap.

This may be checked by removing the distributor cap and looking at the number one spark plug connection. The next plug wire in the cap would be routed to the next spark plug in the firing sequence for that engine, and the direction in which the distributor turns which is either clockwise or counter-clockwise would determine which direction the distributor runs in.

Try Inline 4 Firing Order

What are 4.3L Vortec Cylinder Numbers?

When facing the front of the vehicle and gazing at the engine, the cylinder with the number one corresponds to the first one on the right. The one on the other side is cylinder number 2, and it’s the one in the middle.

The cylinder sequence on the motor for the driver’s side, when seen from the front to the rear, is 1, 3, and 5, while the arrangement on the motor for the passenger’s side is 2, 4, and 6.

How are cylinders numbered in 4.3 Vortec?

The first cylinder on most Chevrolet engines is located on the driver’s side, or the left part of a vehicle if it has a rear-wheel-drive configuration. This cylinder is designated as the #1 cylinder. For cars or minivans with front-wheel drive with a laterally mounted V6 engine, the #1 cylinder is located on the forward side of the engine, on the passenger side.

Cylinders in an engine are sequentially named in a clockwise direction, starting with the cylinder closest to the front of the engine and moving rearward. This means that one bank of cylinders on a V6 or V8 engine with rear-wheel drive or a laterally constructed V6 would all have odd numbers, which is for all of the left cylinders or all of the front cylinders on a laterally manufactured V6.

Check out Straight 6 Firing Order

Chev/GMC Distributor Install 4.3L V6 Vortec

Jake Mayock