1G-GTE Stalling out on removal of Oil cap.

[postfach]

Um, Steve, what's that got to do with the original issue?

If there is a hose going from the rocker covers to the intake after the AFM, then taking the oil cap off is quite obviously going to let unmetered air into the intake, causing the car to stall.

[sergei]

Um, Steve, what's that got to do with the original issue?

If there is a hose going from the rocker covers to the intake after the AFM, then taking the oil cap off is quite obviously going to let unmetered air into the intake, causing the car to stall.

Yes exactly what I was trying to tell.

[fivebob]

It just goes to show how many faulty Toyotas there are then.

No, it just goes to show how little you know about engine management systems, but then again your sig already shows that, there's no further need to prove your ignorance.

As others have pointed out it's normal for an AFM metered engine to stall because unmetered air is being introduced into the intake system.

Crankcase has to be at atmospheric pressure otherwise the oil pressure gauge will never read correctly(if you have one).

And just how do you figure that one out???

Crankcase pressure is constantly varying, it's never really at atmospheric pressure when the engine is running, so what does that do to an oil pressure gauge if your implausible theory is correct???

What about when you fit a vacuum pump to the crankcase, or even a dry sump system???

[postfach]

Crankcase pressure is constantly varying, it's never really at atmospheric pressure when the engine is running, so what does that do to an oil pressure gauge if your implausible theory is correct???

If you're taking an oil pressure reading from the sump

[cat007]

I assume you are still AFM and haven't messed or changed the PCV stuff - is its all stock - then yes, removing the oil filler cap CAN cause the engine to run rough and even die.
Does it die straight away?

Take the cap off, hold (tightly) a piece of paper over the hole, does it get sucked in, or blown out?

Sucked in means your PCV stuff is working properly, and taking the oil filler cap off is causing un-metered air to enter the manifold/engine - which is perfectly normal

Blowing out, means you have buggered rings and possibly poor sealing valves.....which of course is bad.....

[Quint]

^^^ Cheers for all the info guys.

Good to know that its nothing sinister.