I would look at a new mechanic also perhaps? The two motors are fairly different.... if he thinks you have the SPI then when you take it in to diagnose things he may go about it in a wrong approach.
2001 ZX3 2.0L Zetec-
Hatch Nation #42
Going through Rebuild See "The TICK Build Thread" for details (http://www.focusfanatics.com/forum/showthread.php?t=289168&referrerid=62897)