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1988 Chevrolet C3500 Cheyenne 7.4L Excessive Emissions
Posted to GM Driveability on 4/12/2000

This 454 goes into open loop, instantly, when throttle is released. Then mixture goes rich. OTC scan tool readings at idle are: IAC 15, INT 128, BLM 128, RPM 950, O2 .95V, TPS .64V, COOL 194, MAPV 1.07. If I open the throttle slightly (.012'), it goes into...

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car Vehicle Data

1988 Chevrolet C3500 Cheyenne

VIN 2GCHC39N8J
Engine7.4 L / 8 cyl / GAS
Trans4-speed Automatic
DeliveryFI / TBI
EmissionsCalifornia
SymptomsExcessive Emissions
OccursAlways, Idle
Misc.Dually
Message Closed w/FIX

car Vehicle Data

1988 Chevrolet C3500 Cheyenne

VIN 2GCHC39N8J
Engine7.4 L / 8 cyl / GAS
Trans4-speed Automatic
DeliveryFI / TBI
EmissionsCalifornia
SymptomsExcessive Emissions
OccursAlways, Idle
Misc.Dually