// ACES CSV

sample-drive.csv

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

563 samples · 76.0 s

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

Your drive · 76.0 s

0:00 → 1:16

Idle 44% Decel 3% Other 13% Crank 2% Engine off 37%

Click a stretch to zoom the trace to it.

We reviewed this datalog. One item is worth addressing before your next drive.

Fix this first

1. Idle air control
Review · not urgent
IAC avg: 38.5 counts
Adjusted limit: 25.6 counts @ 78.1 kPa

The 35 s this is based on · 0:04 → 0:39 263 samples

IAC Position avg 38.4 · 6 – 26 counts · where ACES wants it

RPM avg 991

0:04 0:22 0:39

What we saw

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.

// Do this in the garage

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 valve authority
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.

// Workbench The full log. Every check above came from these two views.

Time Trace

Wideband O2 sensor pegged

hover to read

ENGINE OFF · 24 S · HIDDEN FROM CHECKS

Start

End

Grid Chart

Where the mixture landed

AFR vs target · by RPM and MAP

Exclude low-confidence cells

MAP (kPa) →

80 70 60 50 40 30 20

500 1000 1500 2000

RPM → 500

Each square is a spot your engine spent time in. Green hit the target. Red ran rich, meaning too much fuel. Blue ran lean, too little. Striped squares had too few samples to trust.

tick = Samples disagree

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45 views

sample-drive.csv

Fix this first

1. Idle air control

Where the mixture landed

Keep this log for good