E30 Zone

Hi all,
Got the 318is last weekend & it had an irratic idle problem. Had a look yesterday to try & find the cause, & firstly i noticed that there is an outlet on the throttle body that has been capped off....

The hose with the bolt in on this picture.


I've look at other pictures on the 'net, & most have a pipe attached that disappears under the inlet manifold somewhere. So my question is, should this be capped, or am i missing a pipe somewhere, & where does this pipe run to?

Secondly, the pipe from the rocker cover goes to a connector somewhere under the inlet manifold, & when this was disconnected, the idle was spot on, with no bouncing. I blocked the pipe from the rocker cover with my hand & the idle was still steady, then i blocked the connector under the inlet that this pipe connects to, & again, the idle was steady. I'm stuck as to what pipe needs replacing. Any help or advice would be appreciated!

Thanks.

the pipe coming from the throttle body is meant to be capped off, mine also had a bolt like that temporarily, absolute nightmare trying to get the blanker from bm, i did eventually get sorted however, only pence.

the air pipes arnt dear, to be honest your better at this age stripping it all down and replacing all the pipes, not a big job,

if your unsure where the leak is coming from, let the engine idle, and spray wd40 or brake cleaner at each of the joints/pipes, in turn, the engine idle will raise noticeably if you have found a leak

Anyone know the number for the blank plug?

get your hand in under the inlet manifold and feel that the hoses are all connected tightly.
also check the connections on the idle control valve also try unpluging the ICV and see if the idle changes?

i had all the breather pipes off mine last week just to check them for crack's etc .. they are a bit of a "right pain!" to refit with the inlet manifold in place