any ideas why the vacuum hose at the intake manifold would be plugged with this small metal “plug”? (BTW cruise control currently not working despite being otherwise looking to in good shape)
PO did it. Definitely not a factory thing.
Look through this thread. Some of the vacuum connections on an early 6.0L v12 are discussed - should be relatively close to your 1992
PS Here is the picture from post 1, embedded into the forum interface:
- Service vacuum to HVAC (Hot Water valve, vacuum motors for vents & de-fog.
- Vacuum to Marelli (Orange hose)
- Vacuum for TH400 vacuum modulator
- Vacuum for the spaghetti system (solenoids, various controls under RH Intake manifold).
Vacuum connection for ECU in boot (26CU for '92) comes from connection to cross over pipe.
This would be the the #1 difference compared to the 6.0L. The vacuum tube to the 36CU is connected to the intake manifold on bank A.
Thanks for the clarification Alan!
Just a thought here … possibly a check port for vacuum gauges, and this is a “cap” to cover it when not in use? 