Engine cranks, but no spark, im stumped Options

[hitcachi]

Well for a little over a week now the Celica has been down. As the title says, it cranks normal but i have no spark. I have replaced so far, the timing belt (because thats what i thought it was at first before i checked for spark), distributor, ignition coil, and igniter. All fuses are good. Very expensive so far and I'm getting frustrated because its still not getting any spark. Reading some past posts, it might be the Starter relay, i haven't replaced that, but i don't know how to test it before just going out and buying a new one. If anyone can offer any suggestions or help i would really appreciate it. Thanks.