Gosh, don't go diddelling around with the IP settings. Check for hose connections, frayed/split (even the tiniest cracks in the ends) and see if the screen that is in the banjo fitting is clogged. Banjo fitting on the IP. Be EXTRA careful to keep even the smallest spec of dirt OUT of the IP/lines.
Is the gasket onthe intake manifold OK..bolts secure?
How abotu the fuel tank...vented OK?
And the filter, gasket not snagged or folded over, lines secure.
If you are in No. VA let me know and I'll drop by to give you an assist.
Eric
:-)