I would check for a loose ground strap or missing ground first. They can make you feel like you have all kinds of gremlins. There should be one at the rear on one of the heads going to the firewall and possibly one on the block.
As for the timing, you should have the key way on the crankshaft sprocket directly up(12 oclock) and the marker on the camshaft sprocket pointing directly towards the crank shaft(6 oclock). Here's an image:
If you check all the simple stuff like vacuum leaks and missing/lose grounds, i would definitely look into making sure the timing is right. If you did not correct the orientation of the sprockets(compensate for the lose timing chain) by lining up the marks before putting the new sprockets and chain on, you're probably a pinch off. You don't have to remove the engine to do it, just pull the water pump and timing cover off.
Let me know if i can help anymore. Good luck.