Hey guys, 1991 acty truck. It wasnt starting. Spark and fuel checked good. I started disconnecting vacuum lines a when i disconnected one thicker line, truck started right up and idol shot up as well. I stuck the line back on quickly and she idled perfectly. With this line connected, the truck wont start. With it disconnected, it starts but idol is high until I plug the line. Interesting part is this line runs all the way up and into the front bumper. . It seems that line regulates air while starting. Anyone know what it is, where it leads to and possibly the issue?? Any advice helps.
