isturbo
New Member
Long time, mates.
Saw a discussion on an Australian forum recently about a 1UZ miss that only showed up at cruising speeds, got worse in hot weather, and was worst with the A/C on. Turned out to be the ignition coils breaking down under heat.
The miss doesn't throw codes cleanly, it's intermittent, and it disappears in cool weather, which sends people down rabbit holes chasing AFMs, O2 sensors, and fuel issues that aren't the problem.
If you've had this failure mode on your 1UZ, share the diagnostic process. How did you confirm it was a coil and not something else? Did you replace one or both? OEM or aftermarket?
Saw a discussion on an Australian forum recently about a 1UZ miss that only showed up at cruising speeds, got worse in hot weather, and was worst with the A/C on. Turned out to be the ignition coils breaking down under heat.
The miss doesn't throw codes cleanly, it's intermittent, and it disappears in cool weather, which sends people down rabbit holes chasing AFMs, O2 sensors, and fuel issues that aren't the problem.
If you've had this failure mode on your 1UZ, share the diagnostic process. How did you confirm it was a coil and not something else? Did you replace one or both? OEM or aftermarket?