Sluggish Acceleration After Head Gasket Job - Knock Sensors Disconnected (Code 52)

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Problem

After completing a head gasket job on a 1992 Turbo Automatic, the car had no throttle response and was extremely hesitant to build power. It ran fine at idle and even built boost with perfect throttle response in Park, but as soon as the transmission was put in Drive, the car would not accelerate or build boost. It also stumbled after letting off the gas.

No throttle response in DriveVery slow to build speedWill not build boost in gearRuns fine at idleNormal throttle response and boost in ParkStumbles after letting off the gasCode 52 (knock sensor) check engine light

Root Cause

The knock sensors were left disconnected after the head gasket job. Without knock sensor input, the ECU logs Code 52 and enters a limp mode that severely retards ignition timing, making the car extremely sluggish under load.

Confidence

High confidence — Multiple community members agreed on this solution

View Original Thread →Posted March 2024 on SupraForums.com