tonight at random my truck started dieing going down the road and at redlights. the motor just cuts off and has to seat for a while before it will crank back up. the fuel pressure is running 58psi and the spark plugs look good. when it decides to run it seems fine and my afr stays where it should be. i have no idea what else to check out without a dtc.

 

check compression,this could be a sign of a weak cylinder or two!

 

Do you have access to a scan tool so you could watch data and see if a signal is dropping out when the engine stalls? Any codes or check engine light?

 

I'd start looking at the grounds on the back of the engine and harness plugs after you run through the obvious stuff.

 

i've logged everything i can think of that hp tuners will support and havent seen any sensors fall off when the engine stalls. it doesn't have any codes that are current.
the grounds are tight and i've been over every plug i can find and they are all latched good. what is the obvious stuff, maybe im not thinking about something obvious

 

Make sure the battery cables are clean and tight.

 

i guess you could check air/fuel/battery

 

you said it has to sit for a bit before starting.. check the fuel pump?
i had a vehicle once where the fuel pump was going bad.. it would stop working.. mid drive...
then id let it sit for about 3 minute.start right up..

 

I know its not a GM but my wifes benz had a faulty cam sensor that would make it seem like the engine was starved for fuel. We would sit for a while and then it would start just fine. A few times while turning the benz turned off and almost hit a pole.
After it was replaced and releared the issue went away.

 

When it dies, does it die instantly, or does it hesitate and loose power for a few seconds? If i dies instantly I would be looking at a crank sensor or some wiring connector is loose. A bad crank sensor will not always set a code.