your mechanic is not upto snuff in diagnosis work - find another one.
Long crank to start usually is attributed to a failing MAF or leaking intake manifold or even clogged injectors (junkyard injectors are a 50% chance to be good).
Fuel pressure leak down is also a culprit - which is easily tested with a fuel pressure tester - if your mechanic is honest to his trade he would have it, if he doesnt then find someone who has, Toyota do not give a test port in their fuel rails - you need to install a T adapter in between the fuel line - Make a tester with a junked fuel line connection union.