Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1984 Mercedes Benz 190D AutomaticFACTORY OEM SERVICE PROCEDURE
Injection Nozzles
NOTE:
For testing, use clean test oil or filtered diesel fuel only. When checking a nozzle, never place hand in front of jet nozzle.
- Prior to testing, check longitudinal bore for free passage. Clean with a .18 mm diameter wire.
- Using Bosch injector tester (EFEP 60 H), energetically pump 5 times through injection nozzle on tester. Then test buzzing of nozzle, slowly actuating hand lever for this purpose (approx. 1 stroke per second).
- During short, fast partial strokes (or least 2 strokes per second) the jet pattern should be narrow and well atomized. If spray pattern is wide or if nozzle just drips, replace nozzle.
- To test opening pressure, move hand lever slowly in downward direction (approx. 1 stroke per second). Opening pressure should be approx. 1667-1812 psi (shutoff valve must be open during test).
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.