Its becoming more difficult to start my b16a.
I've checked that its not my starter & I am getting spark. New ngk spark plugs & wires.
I am receiving fuel I hear the fuel.pump prime the only way to start it is my hand over the manifold.
I do believe it is a vacuum leak.
It sounds as if it will almost die if it gets abit more air.
I used a b16a2 manifold gasket as I couldn't get a b16a one in auto zone.

If any ideas what I can do would.be great!

 

How is it getting harder?

Is it spinning slower?
Is it spinning longer before cranking?

Try this:
Turn key to ON position
The check engine light will come on for ~1 sec
WAIT until the check engine light turns OFF
THEN, turn the key to START

How does that work for you? Any better?

 

it is becoming harder as in it will just roll over and over. not that its cranking slower. or anything just. its as if its stalling alot.

i have cel code on my obd0 ecu.
1cel
2cel
12cel
when i try starter jumping and hand over the intake manifold. it will get better to start but still does not until about 1 minute of cranking...

 

Here is what I would do:

Remove fuel rail and injectors. Inspect for any debris or blockage. Clean and reinstall.
Also check the fuel pressure regulator.
Try to start.
No improvement?
Replace fuel filter
Try to start.
No improvement?
Replace fuel pump. And also make sure to blow out the fuel hard lines to and from the pump.

 

What ECU are you using?
Code 12 is for EGR which I think only exists on the B16 automatic.

When you say you put your hand over the intake manifold, I'm assuming you are putting it over the opening to the throttle body.
This suggests you are either getting to much air so you hand blockage reduces air.
It could also suggest not enough fuel so reducing air makes the mix better for starting - F22 seems to have covered that scenario really well.

When you get it started, how does it run?
Have you even changed the fuel filter or run injector cleaner?
Is your throttle plate closing all the way (might as well clean it while you are looking at it)?

While running, you can check for vacuum leaks by spraying connections, hoses, mating gasket surfaces, etc down with starter fluid. Alternatively, if you have a propane torch, you can leak propane around these same areas. Listen to your idle for changes as it will bump up when you find a leak.