When I start this truck it has an up and down idle,it is sluggish and has no power until it reaches upper RPM.I can hook my scanner to it and switch to read codes or live data and immeadiatly the truck smooths out and runs as it should.I have checked or replaced all sensors,I have replace the ecm,fuel pump ,fuel filter, pressure regulator,tps,iac,and O2 sensors.I have checked all grounds at engine and all grounds and pins at computer. the truck always runs fine as long as my scanner is plugged in and operating but the second you turn it off it will revert back to erratic idle and loss of power. I have been in the mechanic business for 25 years and have never had a problem such as this.any help or advice other than scraping it would be greatly appreciated Thanks
Mar 22, 2012 at 9:26 AM