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Hi guys,

Posting this in the electrical forum since I’ve mostly ruled out mechanical issues. I’m helping out a friend with a 2003 Civic with the 1.7L and automatic (don’t know if it has VTEC or not). The car is hard to start — heavy misfiring during cranking, but if you crank for ~5 seconds while holding the accelerator partway to the floor, it catches and immediately settles into a beautiful idle. I’m in Massachusetts, so it’s pretty cold here right now, but the idle starts out at 1800-ish as it should and then drops below 1k when it warms up without any hiccups or rough idle. If you shut the car down and try starting it again while it’s warm, it has the same symptoms, but again, immediately settles into a good idle once it catches. There is no check engine light, the battery is new, and the starter cranks really strong.

Last week, the car wouldn’t start at all, but after finding and replacing two dead coils, we were able to get it to start as described above. However, it then quit starting and would only crank with no ignition and flash the immobilizer light. We scheduled to have the car brought into an automotive electronics shop in the area to have it fixed, but when we went to call a tow truck this morning, the car began starting again as described above and the immobilizer faults disappeared. We cancelled the appointment at the shop, but are kind of stuck on what to do next.

Does anyone have any thoughts on what might be wrong? Could there be a bad ground that somehow affects the starting but not the running? Could the immobilizer be partially failing but not throwing an error code? Are there other things I’m overlooking? Normally, I would be looking at stuff like fueling issues, IACV trouble, clogged EGR, ECT issues etc. etc. but none of those seem to make sense with how perfectly the runs as soon as it starts.

Any ideas or advice you guys can provide would be really helpful — thanks!

~Jooseppi