Mitsubishi 3000GT shakes and struggles to exceed 35 mph, potential ignition coil pack failure on Mitsubishi 3000GT

Some Mitsubishi 3000GT owners report experiencing shaking and difficulty exceeding 35 mph, which may indicate a potential issue with the ignition coil pack. This problem can lead to misfiring due to a loss of fire or spark in one or more cylinders. Owners suspecting a faulty coil pack can perform a simple test by checking for spark in the wires connected to it. Additionally, heat can cause an ignition coil to short, resulting in performance issues, and replacing both the coil pack and the Power Transistor Unit (PTU) may help resolve this. Furthermore, problems with the Engine Control Module (ECM) can affect the signal sent to the coil pack, impacting the firing of specific cylinders. Testing the ECM ignition drivers can determine if they are functioning correctly. To further diagnose the issue, owners can use a test light to check if the coil pack is receiving a signal when the engine is cranked, as the light should blink if the signal is present. It is advisable for owners experiencing these symptoms to inspect the ignition system components to identify and address any underlying issues.