3 replies to this topic

[madazv8]

Hi,

 

I will be required to retain emissions systems when I do an engine swap.  The MEMS ecu obviously triggers the purge valve on certain running conditions, but my MEMS will be removed.  Anybody tackled this before - long shot I know?    If any luck the R1 engine has one I can utilise,  but not sure....   cheers

[Ethel]

They were fitted to Minis before any of that fancy electronics stuff.

 

They used  one of these where the temp gauge sender usually lives to control it so the purge valve only opened when the engine was warmed up. Expect you could build something similar with a solenoid valve & thermostatic switch of some sort - if not an output off the ECU.

[madazv8]

Thanks.  Yeah I have read that it won't open until the car has temp in it,  but I also thought the ECU fluctuated the valve.  At least,  that's what the Haltec does.  If it is actually open all the time then too easy.

[Ethel]

It was on the same vac take off as the dizzy advance, so would also sense part throttle conditions.

 

 

From the MPI service manual

 

"The EVAP canister purge valve is operated by the ECM. The valve remains closed until engine temperature rises above 70°C. This is to maintain engine tune and catalyst performance. If the valve was to open with the engine cold or at idling speed, the enriched mixture would delay catalyst light off time and cause erratic idling. When the purge valve opens, fuel vapour from the EVAP canister is drawn along a pipe through the valve and into the inlet manifold for combustion."

 

The diagram just shows it connected to the inlet manifold some distance downstream of the throttle. I'd expect it to be self regulating to a fair degree - wider throttle, less manifold depression. Wouldn't be hard to add a bleed valve or flow restrictor though.