š” This often points to a worn delivery valve or a fouled injector. While the manual provides shim specs for the pump, ensure your injectors are "pop-tested" before tearing into the pump itself.
| Document Type | Purpose | Where to Find | | :--- | :--- | :--- | | | Overhaul, calibration, timing, plunger & delivery valve replacement. | Professional diesel pump shops, scan repositories, or pay-per-view auto repair sites. | | Bosch Technical Instruction "VE/VP" | Covers hydraulic principles, governor adjustment, cold-start advance. | Archived Bosch literature (1980sā2000s). | | Engine-Specific Manufacturer Manual | Mounting, fuel line routing, bleeding, timing belt alignment (e.g., VW Fox, Golf Mk3, LT van). | Haynes, Bentley, or OEM dealer service manuals. | bosch pes4a manual
š” Check the shut-off lever. On many PES4A models, the lever must be fully forward to allow fuel flow. If the internal rack is stuck due to old, gummy fuel, the pump will not deliver diesel even if the lever is moved. š” This often points to a worn delivery
If the oil looks like thin, grey diesel, your internal plunger seals may be leaking, diluting the lubricant. | Professional diesel pump shops, scan repositories, or