4.3 idles way to high

I just got through putting in a new fuel supply and return line in my blazer 4.3 vortec 262 ci "W" ,It was running about 25 mph max. and i found the lines were split I found no other damage to the spider assembly,when i finished i started her up and about got launched into the back seat,while i was empressed at first,I thought that my mileage and engine would soon suffer......lol.So my question is can i adjust my idle or is there a different issue here? Blazers rule oh yes.
GO COLTS

I just got through putting in a new fuel supply and return line in my blazer 4.3 vortec 262 ci "W" ,It was running about 25 mph max. and i found the lines were split I found no other damage to the spider assembly,when i finished i started her up and about got launched into the back seat,while i was empressed at first,I thought that my mileage and engine would soon suffer......lol.So my question is can i adjust my idle or is there a different issue here? Blazers rule oh yes.
GO COLTS

No adjustment.
Computer controls idle.

Check for vacuum leaks and vacuum hoses not hooked up.

What year?
TBI or multi port injection?