Originally Posted by rbc

So I checked a few things:

• Good vac coming off the brake booster line to the four way
• I believe this is right: lighter brown line attaches to the four way before the dash and goes through fire wall and presumably delivers vac to ignition. I have the brown line with blue stripe coming out of the fire wall attached to the shut off valve (which is now brand new).
• The brown line with the blue stripe does not have vac when the key is in either the on or off position (presumably it would only have vac when the key is in the off position, to actuate the shut off valve)

So if this all seems right, the problem seems to be that upon moving the key to the off position, the vac delivered by the brown line is not being transferred to the brown/blue stripe line, and hence the car is not shutting off. If the vac cutoff cylinder is gummed with engine oil, how do I clear? Is that the likely culprit? Could a check valve be clogged? I replaced the ignition cylinder last year (not easy to get at). Not again.