Figured out more in my battle
Thanks for all your replies.
The injector problem is a different story but thanks for the help.
I took the radiator out and took it to a pro down the street. It has a 2 layer, 12 fold core in it and it should have a 3 layer zigzag or staggered 14 fold core.
This has got to be my problem. The guy said that the wrong core can greatly reduce the cooling abillity of the radiator! Up to 50% in my case.
Anyway, I have to decide to recore $502 or buy new $800.
Then we'll see if it still overheats. Looks like the previous owner either was ripped off or got cheated.