Just installed the cxj performance intake spacers and the the car barely starts.i turn on the key car idles really rough and the rpms go up and down and it just dies....i think something is unplugged but i cant find what i dont think i have intake leak we tightened them good and put a light layer if silicone but didnt tighten down the upper intake manifold in the numerical order i dont knowbif that matters or or not..

 

Sounds like you may have left a vacuum line off. If you left a sensor unplugged it would throw a code.

If you get it running can you rev it and get past the roughness to keep it running at higher RPM?

This wouldn't be caused by not following the torque pattern as long as you followed some sort of pattern and didn't just torque each one all the way down one at a time.

 

Vacuum leak.

Do it again.

 

I csn rev it but it only stays on for like 5 sec like its hesitant

 

Make sure you didn't split the intake boot. Check every fold in it for cracks. If it's sucking in air that the MAF doesn't know about it will cause problems.

 

I have a aftermarket intake adapter its not the crappy stock one

 

This sounds like when the IACV goes bad on a 5.0. Are you sure you have it plugged in?

Since you didn't say what year car you have, this may not apply to your car.

 

Its a 2002 maxima