So it seems like my truck has a massive vacuum leak. I found a bunch of hoses burnt or broken and replaced them, to no avail it still idles rough and shakes the truck at a stop. So I got the trusty carb and throttle body cleaner out and sprayed around and got a spike near the rear of the upper intake. Are they known to crack? Is there a line back there I can't see? Also, I think the motor has been swapped with a different year. It has thick intake runners with a spot for the throttle and cruise cable on the upper intake manifold itself. The local junkyard swore they pulled off a 97 explorer. The runners are thinner and no place for the throttle cable to mount. Any help would be greatly appreciated. EDIT:: Also sometimes when coming to a stop it idles very high, 25-3000 and gradually comes down back to the shaking and rattling around 700. It is a 5 speed manual.