🚗 Classic Fault — Mercedes-Benz (1968–1976)
W114 M130 twin carburettor synchronisation
💰 Estimated Repair Cost
$20 – $80 GBP
Parts and labour estimate
🔧 Tools Required
Synchrometer or Unisyn carb balance tool
📋 Overview
The twin Zenith carburettors on the 2.8 M130 engine require periodic synchronisation. When out of balance engine runs rough.
🩺 Symptoms
- Rough idle
- vibration through steering at idle
- one bank of cylinders running rich
- poor fuel economy
🔍 Possible Causes
- Unbalanced carburettor throttle plates
- worn carburettor linkage
- air leak on one carb
🛠️ Diagnosis Steps
Use a Synchrometer or Unisyn gauge to balance air flow through both carburettors at idle. Check linkage for wear
✅ Most Confirmed Fix
Carburettor synchronisation and linkage adjustment
82% of users confirm this fix worked (14 reports)
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