Question about GMC C1500

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On a gmc truck 1991 V-8 5 liter engine. The truck starts and runs ok for a while then the rpm goes down and back up to where it was before. It sort of makes the truck surge and slow down. It then returns to normal. It is not a concistant problem at this time. I just fear something may happen and the truck stop and leave us someplace. Thank You

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  • luciano gonzalez Nov 11, 2010

    Thank you for your direction. Sounds good to me.



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1. First step is to change the fuel filter of the truck. After that if the car runs normally everything will be all right.
2. If the problem still occurs then you must scan the Engine Control Module (ECM) using diagnostic equipment connected to the data link connector of the car, in order to pull out all Diagnostic Trouble Codes (DTC) memored. Therefore you will be full informed about bad pieces, and you can replace & repair them. Finally you will be able to erase all faults memored in the ECM & reset the ECM.

Posted on Nov 11, 2010


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