trouble with a tune
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Joined: Dec 2002
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From: houston, Texas
trouble with a tune car was running pretty good until last week. the car started running rough at idle and everything was good after i got up in speed. i hooked up hptuners, put the car into open loop sd and started logging with my wideband. my afr kept floating down low. i started probing wires and found that the wires going to the crank sensor hit the headers and melted. i fixed that and went to tune some more. it is better but the idle is still erratic. i probed the wires at the pcm koeo and found that my 12 volt reference wires for the cam and crank (c1 2,c2 39) were reading 11.43. i checked my other wires and all the 5volt reference wires were reading 5 volts. decided to unhook my cam and crank sensors, probed the wires, and still read 11.43. i pulled the pins from the pcm for the crank sensor and read 11.43 at the cam 12 volt reference. plugged the pins back in and unhooked the pins from the cam sensor, and read 11.43 at the crank reference wire. i tested the pcm grounds to the block and read 14.6mv. i did the big 3 upgrade and added an extra ground on the driver side for the block to chassis. is there a way the pcm could have an internal short without setting a code, or is there a way i could have a bad ground somewhere else that would only effect the 12 volt reference?
Last edited by sroach20; Aug 29, 2009 at 10:20 AM.
