Are you in Surrey as well? If so i guess you know Wayne Ellet from EMC??
ok, so no spraying of wd40 then
All my pipes are attached. I might end up removing the throttle bodies if after i check the pipes and it makes no difference. There was a crack in the plastic riser between the head and throttle body when i re-fitted the head from 2 bent valves.
The idle problem was there before btw.
The crack didn't go all the way through, otherwise i would have replaced it,the gaskets were also good. Perhaps the other side might be worse.
So remove one pipe, block with finger, if rpm's rise that is the culprit?
I still can't get my head around the idle valve and no one has gone into depth.
My understanding is that all the air that goes into the plenum chamber comes through the AFM. At the front of the Plenum chamber sits the idle valve, which is connected down to a 5 way distribution plastic part, which feeds each throttle body after the butterfly so air can get in when the throttle is closed. The other pipe is for fuel vapour recirculation.
What i don't get is, if there is more air going in, as in the throttle body's suck in through the hole, the rpms would increase wouldn't they. So why don't the rpm's increase if there is a leak instead of being low?
Based on this does the idle control valve open, allowing air to go into the throttle body's and then close, so if you blocked off the pipe wouldn't the rpm's drop?