ND2 e-VVT intake holds ~70° at cold idle please expose warm-up/idle offset & idle clamps
Posted: September 6th, 2025, 5:29 pm
Car/Setup: MX-5 ND2 2.0 Skyactiv-G — BBR 4-1 header (primary cat delete), 300-cpsi secondary cat, valved cat-back, OEM airbox + K&N.
Symptom: Rough idle for ~30–60 s after start. Logs show Intake VVT Actual ≈ 68–70° at cold idle (Exhaust ≈ 0°), MAP ≈ 52 kPa, λ ≈ 1.00. When ECT ≈ 50 °C, it settles.
What I tried: Set VVT Intake 1–6 = 0° (500–2000 rpm, 0–0.50 load) — no change.
With the electric intake e-VVT actuator unplugged, Actual drops to ≈ 0–2° and idle becomes smooth ⇒ a warm-up/idle strategy overrides the base tables.
Request (please expose in my ROM):
1. Electric Intake VVT warm-up/idle adder (offset) vs ECT/time.
2. Electric Intake VVT cold-idle target (absolute) vs ECT/time.
3. Intake cam angle limits at idle (min/max) vs rpm/load.
4. Warm-up end conditions (coolant temp / time).
Goal: set offset = 0 below ~50 °C and/or clamp idle to 0–2° (600–1200 rpm, load ≤ 0.40).
Thanks!
Symptom: Rough idle for ~30–60 s after start. Logs show Intake VVT Actual ≈ 68–70° at cold idle (Exhaust ≈ 0°), MAP ≈ 52 kPa, λ ≈ 1.00. When ECT ≈ 50 °C, it settles.
What I tried: Set VVT Intake 1–6 = 0° (500–2000 rpm, 0–0.50 load) — no change.
With the electric intake e-VVT actuator unplugged, Actual drops to ≈ 0–2° and idle becomes smooth ⇒ a warm-up/idle strategy overrides the base tables.
Request (please expose in my ROM):
1. Electric Intake VVT warm-up/idle adder (offset) vs ECT/time.
2. Electric Intake VVT cold-idle target (absolute) vs ECT/time.
3. Intake cam angle limits at idle (min/max) vs rpm/load.
4. Warm-up end conditions (coolant temp / time).
Goal: set offset = 0 below ~50 °C and/or clamp idle to 0–2° (600–1200 rpm, load ≤ 0.40).
Thanks!