This is a re-post that I am making to summarize new info and get new input.

I changed the engine in my 94 4x4 22RE after I skipped the timing chain. The 'new' engine has 115k and an unknown history.

The engine replacement went fine until I set the timing. I can get it to run perfectly when cold, but after it warms up, it runs really rough and almost stalls. I get no CEL or codes.

Things tried so far:
remove O2 sensor (set code, then re-installed and cleared code)
swap in original coolant sensors (2 pcs)
swap in original distributor
swap in original throttle body (with TPS)

I have not yet swapped in the original EGR valve.

Any other ideas would be appreciated.