Bosch D-Jetronic injection faults (B20E/B20F)
Symptoms
Poor starting, lumpy idle, hesitation, black smoke, random stalling. Sometimes won't start at all.
Cause
The D-Jetronic system on the 1800E and 1800ES is primitive by modern standards. Injectors clog or leak, the airflow sensor (pressure sensor) drifts, wiring corrodes, the cold start injector fails. Parts are rare and expensive now.
Fix
Diagnose methodically.
Check fuel pressure first (should be ~28 psi).
Test injectors for spray pattern and leaks.
Check all grounds, these systems are *very* sensitive to poor earths.
The airflow sensor is a common culprit and NLA from Volvo.
Some people retrofit Weber carbs or SU setups and bin the injection entirely.
Injector refurbishment services exist but aren't cheap.
Know something we don't?
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