Yanmar — Fuel injection nozzle pressure inspection
Testing & diagnosis
From a Yanmar service manual — check it applies to your exact model before use.
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Before you start
- Wear protective glasses when testing injection; never approach the nozzle with a hand
Procedure
- Remove carbon deposit at the nozzle hole thoroughly before measurement
- Connect the fuel injection valve to the high pressure pipe of the nozzle tester
- Operate the nozzle tester lever slowly and read the pressure at start of injection
- If measured injection pressure is lower than standard, replace the shim with a thicker one
Tools required
- Nozzle tester Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 3TNV82A eBay $12.99 FridayParts $9.80 SinoCMP $99.00~TNV88 FridayParts $79.28 (VM) injection pressure: 21.57~22.55 MPa (220~230 kgf/cm2)
- Injection pressure increases approx 1.9 MPa (19 kgf/cm2) per 0.1 mm shim thickness
- Nozzle case nut tightening torque: 39.2 to 44.1 Nm (4 to 4.5 kgf-m)
Source: Yanmar service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.