Danny Ashley

old motor was a 2002 5.3 btr cam. dyno tuned/
new motor 2003 5.3 rebuilt ls6 cam.

i swapped motor in. it ran great for a few miles. not thowing these codes and feels like 20% power loss. also hard starting. sometimes takes 3 trys and can have small backfires while cranking.
codes come back instantly when cleared.
P0650 MIL control circuit
P0343 camshaft position sensor circuit high
P0200 injector circuit/open

replaced cam position sensor with an aftermarket one from parts store. ran good for about a mile then back to same. i clear codes they all come right back.

is it possible the ls6 cam previous owner purchases was a front pickup cam? can i tell while its in car?
any ideas why it will run good for a min then sound like its missfiring and run like crap?

Suncc49

do you have hp tuners? Able to log the cam position sensor hi low? wiring harness was perfectly fine before this eh?

Danny Ashley

yeah was fine before.. did a multi meter test. basic meter. had 12v to power wire, 12v when testing ground side.
when testing signal wire i get the following. nothing when car off. when i turn key to on it jumps to maybe 9v ish then creeps down to almost zero. when i crank car over it jumps to 5v and seems to stay there while im cranking car over. i disconnected coils so car wouldnt start while i crank over.
with a basic meter should it show steady 5v whle cranking or should it go up and down?