Just starting out

[Reynjer]

I recently aquired a 1987 320i mainly for my daughters and for something for me to tinker on (which I have not done in a good 15 years). I honestly didnt think I would like it as much as I do but I am really enjoying it. While I am now looking for a nice 325i Manual for me I probably should tune this car up for them.

To start with I found that the car has a slight rough idle and a little hissing sound. Car has a new muffler and exhaust seems okay. So I have started going over the car looking for air leaks and such. In doing so I noticed that there are 3 spots for hoses on the intake manifold. The middle of these appears to be intentionally plugged off. Would any of you fine people have any idea what this should be connected to?

And any good engine schmatics I can view online. I tried to find some that would allow me to try and trace the hose that way but have not had any luck. I was just pointed to these forums and wiki and currently going through them.


Cheers

[Grrrmachine]

At 1987 your car lies in a certain sweet spot regarding engine management. BMW were still tinkering with the Motronic setup, meaning your car will either have a Motronic 1.0 or 1.1 management. This means you'll likely find a lot of info online about your car that doesn't seem to make sense.

There were also some other tweaks around the engine bay. The vacuum hoses that charge the brake servo were simplified, but there were still relics to the old vacuum-driven distributor. For that reason, the intake manifold has multiple vacuum hose ports, but not all of them get used. Less is more, in this case.

The Wiki does have wiring diagrams, but to best understand the engines it's worth reading the Fuel, Intake and Spark pages thoroughly, and clicking around from there. There's a wealth of information in the Wiki on getting these cars back to their original condition, although there's not much else you can do to a 320i other than enjoy it for what it is.

Hope that helps.