Only cylinders 3 and 5 have spark?

If cylinders 3 and 5 are the only ones receiving spark, it suggests that there may be an issue with the ignition system specific to those cylinders. Since you mentioned that your vehicle is distributor-less, it likely utilizes individual coil packs or coil-on-plug ignition.

Here are a few steps you can take to diagnose the problem:

Check the ignition coil(s): Each cylinder typically has its own ignition coil. If cylinders 3 and 5 are not receiving spark, there might be a problem with the coil(s) associated with those cylinders. Inspect the wiring connections and consider swapping the coil(s) with those from other cylinders to see if the problem follows the coil.

Inspect the spark plugs: Ensure that the spark plugs in cylinders 3 and 5 are in good condition and properly gapped. If the spark plugs are worn out or damaged, they may not create a spark. Consider replacing them and see if it resolves the issue.

Check the wiring and connectors: Examine the wiring harness and connectors related to the ignition system, particularly for cylinders 3 and 5. Look for any signs of damage, loose connections, or corrosion. Repair or replace any faulty components as necessary.

Test the power and ground signals: Using a multimeter, measure the voltage at the ignition coil connector for cylinders 3 and 5. Ensure that there is power reaching the coil when the engine is cranking. Additionally, check the ground signal to verify that the coil is properly grounded.

If you have access to a scan tool that can read live data, you can also monitor the signals from the crankshaft position sensor (CKP) and camshaft position sensor (CMP). These sensors provide crucial information to the engine control module (ECM) for proper spark timing. If the ECM is not receiving accurate signals, it may not send spark to all cylinders.

If you are unable to diagnose and resolve the issue on your own, it is recommended to consult a professional mechanic or take your vehicle to a reputable repair shop for further assistance.