white88turboII

so yesterday i got my uim back on and what not..... started it up but it doesnt wanna seem to keep idle when its warm..... it just wants to give out..... replaced most of my vac lines..... spider vac and other vac that were hard and brittle...... i think it's my air bypass syllionoid on my uim that might be doing it because it kinda cracked..... anyone know what any other problems could be..... just here lookin for some input....