Problem: About 5 times, I would leave the car for a brief time (~5-15) mins after driving, and when I came back, it wouldn't start. It would randomly start again either immediately or after leaving it alone for 5-10 minutes. Now it won't start at all. If I leave it alone for a bit, the starter "tries" and gets worse, and worse on subsequent retries, then gets a little bit better after the car sits.
There is no CEL or codes.
Attempts to fix:
- Replaced battery - it's always step 1 and it was time anyway.
- Changed key battery - someone said it might help due to security chip. I don't get it, but whatever.
- Tried jump-starting - doesn't help at all.
Theories: Please help me identify the most plausible / test.
- Relay/fuse (diagram) - Ignition Switch Main? Main Fuse? Ignition Coil?
- "Wire thingy that goes from key cylinder to something" (edit: ...I meant ignition switch) - I have no idea what this is called, but there is a wire that usually signals that the key is turned to start or whatever to the ECU. I think I had this problem on an Integra before. What is this called? Could it be it?
- Key FOB chip / whatever reads it. How do I even troubleshoot this?
- Clutch "safe start position" switch (seems unlikely to me)
Would appreciate any advice on this.