Toyota Repair: engine misses, coil, spark

Question
Dear Vince

I replace the 7A-FE engine with a 16 VALVE EFI engine (not sure about difference between two}, problem is after fitment engine misses at idling and low speed. Plugs fitted are champion RC10PYP4 - NOT SURE IF THIS IS THE PROBLEM
Please help

Answer
There could be a number of issues.  Have you checked your OBD for errors?  Some of the sensors used on one engine may not applicable to your new engine and this can be "confusing" your computer.
Your timing may be off.  Your plugs may be incorrectly gapped.  Are your plugs the ones prescribed?; I use platinum double electrodes.  You may have a bad coil pack or spark plug wire.  Is the miss noticeable at higher rpm's?

Hope this helps.

Vince