TheFu

Have a 2001 CL - around 160K miles. Wonderful car all these years. Always starts right up, except when we visit family near the Blue Ridge Parkway (NC mtns) during high "leaf" season ... mid-October.
The car works great getting there, but it takes 5+ starting attempts to get going. It isn't low temp related - mid-50s over night there still. Always starts fine at home even below freezing.
The starter is cranking fine - very strong. Had over a half tank of 93 octane fuel in the tank, so I wouldn't think it is a fuel issue.

I did move the car once during the 5 days there. It started just fine for that 20 seconds of use around day 3 - that was late afternoon.

Drove home yesterday after finally getting it to start around the 5th attempt. Started right up after a fuel stop at lower altitudes in SC.

Basically, it is just a starting issue in the NC mountains as far as I can tell.

Any ideas? Some dirty sensor somewhere that doesn't seem related? Or should I just wait until next October and plan to get a jump / 10+ starting attempts?

thoiboi

Try cleaning the throttle body and checking the conditions of all the spark plugs.

Hows your air filter?

TheFu

Air filter was replaced 5k miles ago.

I doubt there will be any starting issue for 12 months - it only happens above 3K ft altitude. We live around 900 ft alt. No issues starting today, back at home.
I cannot recall when the spark plugs were changed last - probably 60K miles ago.

Tosh

First I would suspect a gummed-up Idle Air Control Valve. Second, I would check out the PGM-FI relay (aka Main relay), remove it, and reflow the large solder joints on the pcb inside.
Everything there is to know about your Honda/Acura main relay:
How the Main Relay works
When the Main Relay goes bad

https://acurazine.com/forums/2g-tl-p...-relay-931252/