08 Silverado 5.3 intermittent starting problems. Help!

fatboy2vrod

My 08 suddenly wouldnt crank. When I turn the switch all the way it loses all power and the clock resets to 12:00. If I continue to turn it on and off the guages bounce around, the dome light sometimes flicks on and off. There is one click when i try to start it the first time and then all is dead. Additional attempts to start end up with clicking and the guages and dome light acting crazy. If I leave it alone for awhile it will then start but all of the warning lights stay on for like 5 seconds and go off. Once it starts it will start repeatedly until I drive it somewhere and let it sit for 30 minutes or more. Replaced starter, check charging system, the battery read 12.68 volts and just over 11 volts when a load is placed on it. However, it it was the battery, why would it start 5,10 or 20 minutes later and the restart 10 times in a row. 137,000 miles. Could it be the ecm, ignition relay, ground etc. Any help would be greatly aprecciated. Thanks

elainesplay

My 05 Tahoe starts fine but if I turn off the ignition and immediately try to restart it is dead. I jump the battery and it starts fine. If it sits for a while for example I go in a store for 10 or 15 minutes no problem it starts. Only trouble is turning off and immediately trying to restart. Help please. 

Mr_Shiftright

Have you tried jiggling the gearshift when this happens?