I have a problem that hopefully someone can put me in right direction. I have a 89 turboII. It just got a jdm engine put in it. I have sorted out the vaccume lines and believe everything is in order. Problem is it doesn't like to start very well and when it does it shakes like a bad missfire. If I give it a little gas and got to about 1500 rpms it smooths right out like there's no prob. wondering if this is maybe typical of a bad sensor or just a missfire. I have spark on all plugs not sure how good of a spark though. Thoughts?

timing?