I just swapped chevy 03 5.3 flex for 05 gmc 5.3 flex . I only used the 05 block and heads . everything else stayed from the 03 . It is misfiring even after new plugs and wires , I am sure all connections are good . any ideas what my problem could be ?


Asked by Sep 20, 2007 at 09:01 PM

Question type: Maintenance & Repair

6 Answers


Was it running OK before the swap? Maybe the crank sensor got damaged during the swap. BTW, why did you need to swap an '03 already?


driving through unfamiliar area and ran through some water and sucked it up in intake subsequently threw rod .


I'm liking the crank shaft position sensor on this one. When you say misfiring, do you meant one cylinder in particular, or the timing is just plain off in general?


multiple cylinder misfiring predominatly 31 & #&


performed a crankshaft relearn , was successful . Still the only code im getting is multiple cyl. misfire .


#1 & # 7

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