Electronic Datasheet:
Mosaic Electronic Component Datasheets
ALLDATASHEET.COM
Automotive Communications:
OBD2 Network Standards
Introduction to the Controller Area Network (pdf)
Calculators:
Volumetric Efficiency Calculator
Diagnostic Resources:
Understanding Fuel Trim
ROTKEE Waveform Library
Other Great Resources:
Chris Brown’s Squiggly Lines
TrailBrake.net
Harness Building:
Professional Mil-Spec Wiring Harness Construction