[svxfiles]

Originally posted by oab_au


Just thinking over breakie, From your discription, I think it is either the BTP valve, stuck closed, or it is not getting vacuum, to open it.

When the engine gets to temp, the ECU turns on the EGR Solenoid, this puts manifold vaccum on the EGR valve, to open the exhaust path. It then relies on the BTP Valve to bleed off vacuum to only allow the EGR to open when the throttle is in the cruse position. This is set by the drilling in the throttle bore that is opened and closed by the throttle plate position.

With this BTP valve not working, as soon as it reaches temp the exhaust path is opened, regardless of the throttle position, idle, full throttle, backed off,,,,,,,,,,,,,

This is the vacuum control valve that you have mentioned. Yes it is like a vacuum leak, except that the drilling is covered at idle by the throttle plate. It is this leak that bleeds off the vacuum to prevent the exhaust path from opening at the wrong time.

Harvey.

I allways thought Aussies spoke english??