I just swapped a ka24e from a hard body, into my 89 240 and I got everything connected correctly swapped the intake on changed the oil pan and stater. Now I go to start it and it cranks it turns on and then dies immediately if i'm on the gas it will stay on but it's super rough Idk what to do. I've checked the injectors, maf, iac valve, tps, nothing is working i'm extremely confused.

After running it for a bit or even just leaving key on for a bit. Check the engine codes. That computer will tell you what it has problems with keeping it from running.

Good luck,
rob