🚗 Classic Fault — Toyota (1984–1989)
MR2 Mk1 4A-GE T-VIS butterfly stuck open or closed
💰 Estimated Repair Cost
Up to $80 GBP
Parts and labour estimate
🔧 Tools Required
Inlet plenum removal tools, carb cleaner
📋 Overview
The T-VIS (Toyota Variable Induction System) butterfly valve sticks with carbon, causing a dramatic power hole around 4200rpm.
🩺 Symptoms
- Strong power hole between 3800-4500rpm
- engine feels strangled then suddenly pulls hard above 4500rpm
- rough idle
🔍 Possible Causes
- Carbon-stuck T-VIS butterfly
- broken T-VIS actuator rod
- failed vacuum solenoid
🛠️ Diagnosis Steps
Remove inlet plenum and manually operate T-VIS butterfly — should open and close smoothly. Spray carb cleaner to free carbon
✅ Most Confirmed Fix
T-VIS butterfly clean and solenoid test
82% of users confirm this fix worked (29 reports)
🩺 Related Symptoms
🔗 Other Toyota Faults
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