89 2500 starts fine then dies after warm up

[jrruta]

i got an 89 pick up for 400 bucks! the thing has what i think is a #7 rod bearing noise. it's pretty beat up but the tranny was rebuilt about a year ago and it's got the 14bolt 6 lug rear. the other day i went to start it, it started right up, no rod noise, left it idle for about 20 min (it makes the rod noise when the engine is warmed up) while i threw some firewood in it. then it died. i tried starting it it would start right up and quickly die, each time i tried to start it it would start harder each time and die right away.

i let it cool down for about 5 hrs came back and it started right up again and idled fine. there are no codes popping up. i even hooked my scan tool up all i got was 12. i'm wondering if it's the knock sensor because of the rod noise. this is just my beater truck (i'd like to just drive it till the motor blows then swap the tranny in my CUCV truck) is there anyway i can rig this truck to stay running after the warm up cycle? i don't care if i get crappy fuel mileage. any help would be appreciated.