G 20 3/4 Ton Van V8-379 6.2L DSL VIN C FI (1984)
1.
Retard ignition timing as much as 4~ from specification if spark knock occurs at low altitude.
2A.
Adjust the primary choke vacuum break from 24~ to 22~ on
automatic transmission models.
2B.
Adjust the primary choke vacuum break from 24~ to 22~ on
manual transmission models.
3A.
Adjust idle speed from 600 RPM to 525 RPM in D on automatic
transmission models.
3B.
Adjust idle speed from RPM to 550 RPM in N or manual trans-
sion models.
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5.0L and 5.7L Federal
1.
Adjust choke vacuum from nominal 26~ to 24~ on automatic transmission vehicles. Manual transmission vehicles do not require adjustment.
2.
Do not adjust curb idle on any models.