D250 3/4 Ton Pickup 2WD V8-318 5.2L VIN Y FI (1988)
Air/Fuel Mixture: Adjustments
CAUTION: Some models are equipped with a factory adjusted throttle plate position set screw. Never attempt to adjust idle mixture using this screw!
Idle mixture is electronically controlled by the Powertrain Control Module (PCM), and is not adjustable.
If an idle mixture problem is suspected, check oxygen sensor and feedback system. SEE Computers and Control Systems.
