ISO 4008-2:1983

Overview

ISO 4008-2:1983 - Road vehicles - Fuel injection pump testing - Part 2: Static conditions - specifies the requirements and characteristics of test benches used to calibrate fuel injection pumps for compression‑ignition (diesel) engines. It applies to test benches for pumps delivering up to 300 mm³ per injection per cylinder at full load and defines static-system features, measurement accuracy, instrumentation tolerances, and acceptance testing (type and field tests).

Key topics and technical requirements

The standard focuses on static test-bench elements that ensure consistent, repeatable pump calibration. Important technical requirements and features include:

• Scope: Test benches suitable for calibration of fuel injection equipment for compression‑ignition engines (≤ 300 mm³/injection/cylinder).
• Measurement principles: Delivery from each injector must be measured and the average specific delivery Q reported over not less than 25 strokes. True (absolute) delivery is established by collecting a large sample and comparing volume to counted turns.
• Accuracy limits (type and field tests):
  • Overall measurement error for many type‑test systems: e < 1%; for systems with specific manufacturer instructions: e < 2%.
  • Zero error ≤ 0.5% of graduate capacity.
  • Count error ≤ 1% of the basic count increment or 0.5 turns, whichever is smaller.
  • Measurement system variation targets (where specified): < 0.5%.
• Instrumentation tolerances:
  • Calibration fluid temp: 40 ± 2 °C; thermometer tolerance ±0.5 °C at 40 °C.
  • Pressure/vacuum gauges: ±1% of reading or ±0.03 bar, whichever greater.
  • Driveshaft tachometer: ±0.5% of reading or ±5 min⁻¹, whichever greater.
• Hydraulic and mechanical details:
  • Supply pipe: length 1 ± 0.1 m, inner diameter ≥ 9.5 mm, internal volume elasticity 500 mm³/bar at 40 °C.
  • Graduates: minimum graduation pitch 1 mm; smallest graduation must not exceed 1% of total volume.
  • Filtration to ISO 4020/1 category 2; no filter bypass allowed.
• Testing regimen: Acceptance testing includes both a type test (design capability) and field test (periodic on‑bench verification). The annex contains test methods, record sheets and analysis forms.

Applications and who uses it

ISO 4008-2 is used where precise, repeatable calibration of diesel fuel injection pumps is required:

• Fuel injection pump and nozzle manufacturers (design validation and production calibration)
• Vehicle OEMs and powertrain test laboratories
• Service stations and heavy‑vehicle workshops conducting pump adjustments
• Independent testing and certification labs ensuring compliance with manufacturer specs

Related standards

Referenced standards critical for full application include:

• ISO 4008/1 and ISO 4008/3 (other parts of fuel injection pump testing)
• ISO 4010, ISO 4020/1 & /2 (filters), ISO 4093 (high‑pressure pipes), ISO 4113 (calibration fluid)

ISO 4008-2:1983 provides the static test‑bench framework essential for accurate fuel injection pump calibration, helping protect engine performance, fuel economy and emissions control.