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1990 GMC 3500 7.4L Poor Idle Quality, MIL Lamp on
Posted to GM Driveability on 6/24/1999

Hi there, this one ton c/c with 454 will start,but runs poor and the ses light blinks rapidly constantly, even when runnning. Had code 51 but not sure if its a old code. I tried 3 different computers and proms and no luck. Master tech cannnot commun...

 
Message Closed w/FIX

car Vehicle Data

1990 GMC 3500

VIN 1GDHR33N1L
Engine7.4 L / 6 cyl
EmissionsOBD
SymptomsPoor Idle Quality, MIL Lamp On
OccursAlways
Misc.R Series

Trouble Codes

51testing and results
Message Closed w/FIX

car Vehicle Data

1990 GMC 3500

VIN 1GDHR33N1L
Engine7.4 L / 6 cyl
EmissionsOBD
SymptomsPoor Idle Quality, MIL Lamp On
OccursAlways
Misc.R Series

Trouble Codes

51testing and results