86 MINIVAN 4.3 220 TBI

1986 Chevrolet Astro

86 astro minivan runs rich and idles rough when stopped at a light but runs fine while driving?
i replaced most sensors, mapp, idle positioning, ECM, IAC. Could it be the fuel metering?
March 16, 2011.

Probable causes of an engine running rich are as follows: 1. Excessive fuel pressure can be cause by restricted fuel return line
2. Defective Oxygen Sensors.
3. Leaking injectors and fuel pressure regulator.
4. Coolant temperature sensor out of calibration.
5. Restricted air intake system.

Mar 18, 2011.