Am getting error code P0400 and am just about 100% sure that at 2500rpm upwards do not have enough vac. On engine start up immediately pulls at least 25 ins hg but on increasing revs the vac levels fall to 18-19 and the vac operated recirculatory air switch does not work until the levels come back.
Have checked individual components with mityvac and all hold vac ok.
If I apply mityvac to vac line side of solenoids they appear to take air through 3rd port with breather attached.
Also they appear to be open straight through but this is unenergised.
I imagine this to be a 3 way valve and when unenergised to allow atmosphere back into valve to allow to return to unvacuumed state.
Should it be posssible to put mityvac on inlet side of valves and pull vac or are they possibly normally open and close on powering up.
The 2 valves in question have the following numbers on them
091 58 200 on wastegate
091 28 022 on valve on inlet manifold closest to head.
Should I be able to put mityvac on vac line from pump and pull vac because at present I lose it through the two valves.
Any info gladly taken on board.