4.0 V8 Engine — Tuning Data (Discovery 1)

Type - V8 4.0L

The firing order of the cylinders is 1-8-4-3-6-5-7-2

Cylinder numbers

• Left half block - 1-3-5-7
• Right half block - 2-4-6-8

Cylinder numbering from the crankshaft pulley

Spark plugs

Manufacturer/Type: Champion RN11 YCC

Gap: 0.90-1.00 mm

Ignition coil

Manufacturer: Lucas 2D 1S2

Type - double

Compression ratio: 9.35:1 and 8.2:1

Fuel injection system — Sagem - Lucas GEMS8

Valve timing	inlet	release
It's opening	28° before TDC	66° BDC
It's closing	77° after BDC	39° after TDC
Duration	285°	285°
Maximum valve lift	108° after TDC	110° before TDC

Idle speed (controlled by the GEMS system)

All additional loads are disabled - 700±20 rpm

Idle speed setting - not adjustable

The idle air control valve is tested with the TestBook tester

CO concentration

Vehicles without heated oxygen sensors - 1.5%±0.5%

Fuel

• 9.35:1 — with a neutralizer AI-95 or higher, unleaded
• 8.20:1 — with a neutralizer AI-91 or higher, unleaded
• without a neutralizer - AI-91 or higher, leaded is allowed