// ACES CSV

sample-drive.csv

1977 Chevy P30 — 496 ci, 100.53 lb/hr injectors

563 samples · 76.0 s

Time Trace

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Start
End

Grid Chart

AFR diff · RPM × MAP

MAP (kPa) →
80 70 60 50 40 30 20
-1.54
-2.50
-3.80
-
-1.42
-0.16
-
-0.02
-
-
-
-
500 1000 1500 2000
500

Blue = lean (actual > target) · Red = rich · Green = good · low confidence due to few samples

Tuning Report

Prepared from a 76.0 s run

Jul 8, 2026

Report № sample · Sheet 1 of 1

Vehicle: 1977 Chevy P30 — 496 ci, 100.53 lb/hr injectors

Log: sample-drive.csv

Run: 76.0 s · 563 samples

Coverage: Idle (44%) · Decel (3%) · Crank (2%)

We reviewed this datalog. Idle mixture looks good, Idle stability looks good. 1 item(s) are worth addressing before your next drive.

Recommended attention

  1. 1. Idle air control

    IAC avg: 38.5 counts
    Adjusted limit: 25.6 counts @ 78.1 kPa

    IAC averaged 38.5 counts at warm idle — above the 6–20 count band ACES targets in neutral. That high, the IAC is carrying airflow the throttle blade should, leaving it less authority when load changes. This log reads 78.1 kPa barometric, so the limit is elevation-adjusted to 25.6 counts — set the throttle stop at the lowest elevation you drive, since counts read higher up high.

    Suggest: Open the throttle plates (throttle shaft adjustment screw clockwise) until IAC Position reads between 6 and 26 (elevation-adjusted from ACES's 6–20 sea-level band) at operating temperature — that band leaves the valve room to add or remove air as load changes. If TPS rises above zero, redo TPS Autoset.

Checked · no action
  • Idle mixture
  • Idle stability
  • Idle air control (low)
  • Idle air control steadiness
  • Throttle position at idle
  • Charging
  • Cranking voltage
  • Fuel trim correction
  • Tip-in mixture
  • MAP sensor

Not enough data to judge: Cruise mixture · Injector duty cycle

Log a longer drive that holds these conditions — steady idle, some cruise time — and we'll call them on your next upload.

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