no power, installed Gillis valve

I just installed a gillis valve on my 88 with an ihi.
When you get on it, it builds a couple pounds of boost, then falls on it's face, like hitting the brakes.

What should I check?

Assuming you installed per the instructions and set the valve per the instructions, then the problem may be leaking at the I/c hoses.

I'm going to start over tonight, everything seems to be right, but it is not building over 5 pounds, and then shuts down.

All set, it was the intercooler.

ever started on something when you knew it was going to get dark out, but you just had to try it out.

I didn't even have the clamp touching the hose, it was on the I/C pipe.

Thanks for the help