The firing order for this engine is 1-8-4-3-6-5-7-2. This sequence applies to the 5.7-liter V8 used in the 1999 Chevrolet Tahoe and related GM trucks and is the ignition sequence the crankshaft follows during operation.
In this article, we break down what that means for the engine’s layout, how the cylinder numbering corresponds to the firing order, and practical notes for diagnosing ignition timing or performing maintenance on a 1999 Tahoe with the 5.7L Vortec.
Engine layout and cylinder numbering
Chevrolet’s small-block V8s use two banks of four cylinders. On a typical Chevy 5.7L Vortec, the cylinder numbering is arranged so that the front-most cylinder on the passenger side is 1, followed by 3, 5, and 7 toward the rear. The driver side bank runs front to back as 2, 4, 6, and 8. The firing order then determines which cylinder fires next as the crankshaft rotates.
Firing order and cylinder mapping
The following list shows the ignition sequence that the crankshaft follows for the 1999 Tahoe 5.7 Vortec. Use this order to diagnose timing issues, set timing marks, or verify ignition component alignment.
- Cylinder 1
- Cylinder 8
- Cylinder 4
- Cylinder 3
- Cylinder 6
- Cylinder 5
- Cylinder 7
- Cylinder 2
The sequence above corresponds to the standard Chevrolet small-block firing order: 1-8-4-3-6-5-7-2. In practice, this means the spark plugs fire in that order as the engine turns, and the cylinder numbering described (front to rear on each bank) helps technicians locate the correct cylinder when performing diagnostics.
Notes for maintenance and verification
When working with timing components or ignition wiring, rely on the factory service manual for exact procedures, torque specs, and any sensor-based indexing that may affect ignition timing, even though the firing order itself remains constant for this engine family.
Bottom line
For a 1999 Chevrolet Tahoe fitted with the 5.7L Vortec, the firing order is 1-8-4-3-6-5-7-2. Cylinder numbering follows the front-to-back layout on each bank (passenger side: 1-3-5-7; driver side: 2-4-6-8). Verify with the service manual when performing ignition work or timing procedures.
Summary
In short, the ignition sequence for this engine is 1-8-4-3-6-5-7-2, mapped to two banks of four cylinders with the numbering described above. This order remains the standard for the 5.7L Vortec in the 1999 Tahoe, and precise mapping helps ensure accurate diagnostics and timing alignment.