I purchased a 95 4 runner with a bad 3vz engine. Basically it had a loud knock. I bought a 89 3vz motor that had recently been rebuilt and had someone do the swap for me. He was only able to use the block and heads from the 89 motor and swapped out all other parts from the 95. The engine starts up and runs fine until it gets warm then it loses power and sputters.

Is there any reason that the 95 parts would be incompatible with the 89 block and heads and could this be causing the problem?

Thanks for any help!!