Need help. Fuel Injectors keep spraying when truck stalls

[Bruno13]

Hello. To keep a long story short, I bought a 87 R10 recently. Ran great then. Now it will crank, idle for a couple seconds and conk out. Replaced fuel filter, gas tanks, fuel pump, tank selector switch, oil pressure sensor, oil pressure switch/fuel pump switch, fuel pump relay, and finally, the distributor. After replacing the distributor, it actually would fire up faster, and idle for maybe 10 seconds, before stalling. Now, when it stalls, the fuel injectors keep spraying!! If I turn it off by key it is fine, it is just when it stalls out.
Any ideas? I checked the ADL and only got a code of 12, nothing more. ECM? Help Please

 

[4WDKC]

Sounds like your battling two issues first if the injectors functioned correctly with the old dist. I am thinking the ICM in the new module is bad. It tells the ecm when to fire ignition and injectors, swap it for the one from the old dist.Second it sounds like the reason it was dying is the IAC take it out clean it but do no move the position of it. If there is something blocking it cannot control the idle and could make it die. try these things and report back.