7M Intermittent Idle Miss Fix - Coil-On-Plug Conversion Using 2JZ-GE Coils

Electricalintermediate✓ OP Confirmed

Problem

7MGTE has an intermittent 'bump' miss at idle that feels like a random misfire. Often mistaken for an air/fuel issue. The stock coil pack setup degrades over time and can leak voltage, causing occasional misfires especially at lower RPMs.

Intermittent 'bump' or miss at idleRandom feeling misfire at low RPMSmooth running at higher RPM/boost but rough idleIssue persists despite air/fuel troubleshooting

Root Cause

Degraded stock 7M coil packs leaking voltage, causing intermittent misfires at idle. The aging OEM coil pack design is prone to voltage leakage at lower RPMs where inductive ignition is used.

Confidence

Moderate confidence — Original poster confirmed this resolved the issue

View Original Thread →Posted March 2007 on SupraForums.com