themadracoon
Hi all,
I have a 240GL, 1984, all standard. There is a small device on the bulkhead, almost centre of it, with an electrical plug and 3 vacuum ports: one points to the passenger side, one to the driver's side, and one to the front of the car.
The vacuum hoses were off, perhaps due to shrinkage, and the ends were split. Looks like the passenger side port connects to the intake manifold, the driver's side to a port under the air flow plate (where another port connects to the vacuum advance).
I can't find the 3rd hose. Where should it connect to? And what is this device/what does it do?
TIA.
BradC
That's the idle up valve for the A/C. It connects to a valve on the intake manifold that adds extra air past the throttle plate when vacuum is applied to it, so when the A/C is off the outlet is connected to atmosphere and when the A/C is on it connects to vacuum on the intake manifold.
themadracoon
Thanks BradC. So I can leave the forward-facing port open to atmosphere? I don't hear the AC relay kicking in when I turn on the AC knob (with fan on) so I won't know if the idle up valve is working or not until I sort out the relay.
BradC
Yeah, it gets left open. If you want to test it, un-plug the wire going to the A/C compressor and put 12v on the engine side of that wire and the idle should come up.
The vacuum element of the idle valve (the one on the intake manifold) tends to get gummed up, but it's all just "snapped" together so you can pull it apart for cleaning from memory. Bear in mind this is relying on 13 year old memory here, but I'm pretty sure it's right.
themadracoon
Great! Thank you BradC