2004 Jeep Grand Cherokee Limited DIAGNOSIS AND TESTING – VACUUM RESERVOIR

download 1. Disconnect vacuum hose at speed control servo and install a vacuum gauge into the disconnected hose. 2. Start engine and observe gauge at idle. Vacuum gauge should read at least ten inches of mercury. 3. If vacuum is less than ten inches of mercury, determine source of leak. Check vacuum line to engine for leaks. Also check actual engine intake manifold vacuum. If manifold vacuum does not meet this requirement, check for poor engine...