1993 Mazda RX-7 — old 6V-to-12V conversion has decades of splices — anyone dealt with this recently?

Intermittent stuff lies if you only catch it once. A pressure test beats staring at a dry driveway if the 1993 Mazda RX-7 is losing coolant with no puddle. Save the big job until that test fails. On “7 — old 6v-to-12v conversion has decades,” that was the fork that mattered for me. That's the whole play. Happens in gear, not in park, for what that's worth.

I wouldn't throw parts yet. Move a coil or plug on the 1993 Mazda RX-7 if it's cylinder-specific and see whether the code follows. Don't erase codes until someone who can help has seen them. This is from a 1993 Mazda RX-7 in Portland with 209,000 miles. If they can't show the line item, I assume it's hiding. No warning lights, which is why I'm documenting it.

Log the conditions before you spend. A pressure test beats staring at a dry driveway if the 1993 Mazda RX-7 is losing coolant with no puddle. Save the big job until that test fails. On “7 — old 6v-to-12v conversion has decades,” that was the fork that mattered for me. Run the total, not the monthly, before you commit. If the story changes I'll post the new data.

Start with the test that can prove you wrong. Swap the cheap/easy piece first on the 1993 Mazda RX-7 and see if the fault moves. Save the big job until that test fails. Write the result down so the next test isn't a repeat of the last one. Your commute and mine probably aren't the same, but the test still applies. Video is ugly but it shows the hesitation.

If it were in my driveway, loaded-suspension checks on the 1993 Mazda RX-7 catch play that a wheels-hanging inspection misses. You'll know quickly if you're on the wrong tree. If it doesn't change the out-the-door or the repair estimate, it's noise. I'd sleep better after that step, even if it finds nothing. Cold start is when I can actually reproduce it.