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1993 Chevrolet Suburban 2500 Question: misfire when cold -misfire when shifting



, 7.4L V8, Saluda, SC, February 27, 2009, 13:52

no misfire when timing set wire is disconnected. no codes. runs fine if wire is left disconnected after timing is aet but code does ahow. work done so far replace distributor,plugs, wiring,trans wiring and selonoids, all wiring for damage, ecm(2), idle air control,map sensor,EGR gasket. Same problem persists,190k miles.Problem started after vehicle sat for one week

2 Answers
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  • Medium-star Best Answer
    February 27, 2009, 22:49

    It sounds like you may have a bad engine computer ground. Wiring diagrams available from may show where. They could be on the bell housing bolts, the engine block, or on one of the intake manifold bolts. The computer grounds must be clean and tight - make sure they are.

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  • Answer #2

    Visitor, November 25, 2010, 12:47

    Check your timing.

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