'84 633CSI High Idle

[Stikk-O]

Hi everyone! Thank you for welcoming me. I'm excited to be a part of this family and my baby is a 1984 633CSI with the M30B32. Recently purchased, the PO stated it runs and drives but he was just in the process of swapping the interior. With a new battery in it, it starts right up every time but after about 10 second, it'll hold the idle high, to about 1800-2000 rpm. I've been reading the forums on here and I've done every other check to the best of my abilities, but I've come to narrow my blame on the Temperature Switch. I hope to be correct but there is also a torn and exposed wire on another sensor/switch on the water housing. When payday comes around, I'll be doing a refresh on it like plugs and oil but as of now, my goal is to just get it stable. Thank you and any advice is tremendously appreciated.

[plip1953]

Can't you do a simple resistance check across the terminals of the temp sensor that you think might be faulty?

[Doctorbeer]

Temperature switches may be rotted out. (The front one on the left in the photo, and the very far rear one looks like the wires are broken) I had this same issue.

If you peel the rubber boot back, it may or may not have the BMW resistor fix that was done back in the day. Mine was broken and thus the switch did not work and caused high idle.

I would test and replace them if they fail the multi-meter and just from looking I highly suggest rewiring that rear one.

I did this in my project thread.

http://www.bigcoupe.com/phpBB2/viewtopi ... 25&t=31422