timing belt- what did i do wrong?

I just installed a timing belt, tensioner and idler pulleys on a 1998 countour gl with the 2.0 ztec vct engine. I followed the instructions from alldata and the ones that came with belt. I also used the tool to hold the cams in place and the pin to hold the crankshaft in place also.

Now, the engine idles just fine- real smooth. But under load it shakes and pops. Sounds like a timing issue to me, so I tore it back down to make sure all of my marks lined up and the cam tool fit back in. The exhaust cam was just a little bit off. So i redid the belt install and tension and the cam lined up after 2 engine roations.

I started it up and same situation. Idles fine but misses and pops under a load. I checked the scant tool data and found the vct cam timing showing -15 deg at idle and increases to positive numbers as engine speed increases. I also found that the overall engine timing is around 30 deg. This sounds like too much but I cannot find specs for total timing or vct timing.

Im convinced that this is a timing problem, but I cant figure out where I went wrong on the installation. Please help me with some ideas. Thanks.