Stalls when I take off the oil filler cap

[howie149]

I just bought a 1989 Carrera and when I go to check the oil (per the proper process with engine running) and take off the oil filler cap it stalls. If I put back the oil filler cap it runs fine. Any ideas on 1) Why and 2) How to check the oil level properly without engine running?

Edited September 4, 2010 by howie149

[wvicary]

It's stalling due to the fuel mixture going lean. You have a vacuum leak some where and one of the most common causes is the line going to the fuel pressure regulator. When the air filter is serviced the vacuum line often gets knocked off. There is also a black plastic valve connected to the oil tank fill neck which is part of the PCV system and has a vacuum line going to it. The line gets damaged or the valve itself fails and can cause the same fault.

There is no way to accurately check the oil level without the engine running or at temperature.

Edited September 9, 2010 by wvicary

[pete917]

The engine has to be running and with oil up to temperature when checking oil level. You cannot do it any other way

[howie149]

The engine has to be running and with oil up to temperature when checking oil level. You cannot do it any other way

I'm confused because one person says to check the oil hot and running and the other says cold and not running.

[wvicary]

Sorry. I meant to say "without the engine running or at temp". I'll edit and correct my post.