under full throttle it runs great!!!

This is a sure sign the fuel side of the injection system is likely to be fine.

For the injection to meter out the correct amount of fuel, nearly all the air has to go around the metering flap. At idle, the vacuum is highest, so any leaks will leak much more profusely & the ratio of air coming through the leak vs. air coming around the metering flap is much higher.

If you take an injector out of it's hole, to see what's coming out at idle or while you are cranking it over, you have to block that hole in the injector or you will get nearly nothing.

Things to check:

1.Make sure the hoses are the right way around on the manifold. The brake booster goes on the nipple with the big hole in it, the blowby hose goes on a larger looking nipple that has a small 1/8" hole in it.

2.Look for cracks or splits on the big concertina hose that connect the manifold to the metering unit.

3.Check for leaks around the injectors & manifold. A can of ether (Aerostart) is very useful for finding leaks.