Question concerning Vacuum

[1WheelWonder]

This may seem like the Supreme Newbie Question of the year but would poor vacuum cause starting issues. I have finally finished my fully built KA and am trying to work out all the little bugs. It idles perfectly at 900rpms but only pulls 10 pounds of vac, this would cause a really rich condition effecting start up right? Again I am sorry for the newb question but I am starting to pull my hair out.

[KATwo40]

Holy vacuum leak, Batman! You really need to get that fixed ASAP before trying to diagnose anything else.

[rotorimp]

Low vacuum will not cause hard starting--but what ever is causing the leak is. hows the timing? IACV, EGR, all vacuum lines hooked up?

[coolbone28]

Ya, low vacuume is not a cause, it is an effect. something is causing you to hage low vacuum. As previously mention a vac leak might cause it, But i think it would have to be a pretty big sized leak to affect it that much. Cam timing is also a big factor in vacuum. It could be off just a slight degree and cause crappy vacuum.

[SeanC]

what kind of cams are you running?

[NateDogg]

I had the MAF wires crossed up and was gettin 3V at idle. Approx 200hp worth of fuel. THat caused the plugs to foul and the engine to only pull 12" vacuum.

All I needed was new plugs.

Check your wiring and fuel injectors for leaks.

[KATwo40]

Boost leak tester FTW!!!

[1WheelWonder]

I am running stock cams and am in the process of boost leak checking right now. So far I have left a vacuum line unplugged on the throttle body and where my maf is(blowthru). I am checking each section individually then I will check the whole system. Thanks for the advice and keep it coming.