Leaky oil pan gasket cause a vacuum leak?

[TorqueEffect]

I know it sounds a bit silly, but with a hose feeding all that metered air from the crankcase straight from the valve cover, if you were to have any leaky gaskets that could allow extra air into the crankcase, couldn't that cause a lean condition?

Because I have a vacuum leak. And a pretty bad oil pan gasket, and having quite a time trying to locate the air leak.

The leak seems to only happen under some throttle. Holding the throttle steady past 2k rpms makes it lope.

Last couple years ago I had a cheap vacuum gauge from eBay, and the men's would violently flutter back and forth under acceleration. I thought the gauge was just bad at the time. But now I know for sure there is a vacuum leak somewhere.

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[TorqueEffect]

Nevermind I am a dummy. I just tested my theory and it didn't hold water. lol

unhooked the valve cover hose and plugged the intake side with the my thumb, and held the throttle cable and it still loped.

Also did this with the brake booster hose too.

So it is either down to bad manifold and plenum gaskets, or injector o-rings, nothing else seems to make a difference. all the vacuum hoses and caps have been checked, even the hidden one underneath.

[bravekozak]

Have you tested your fuel injectors?
Or take it to a shop and have them scoped for a waveform analysis.

Anyway, I learned about a noid light.

Does anyone know which noid would fit our Festivas?

Noid, noid, noid.

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Or, possibly plugged EGR valve? or weak valve spring?

[TorqueEffect]

Have you tested your fuel injectors?
Or take it to a shop and have them scoped for a waveform analysis.

Anyway, I learned about a noid light.

Does anyone know which noid would fit our Festivas?

Noid, noid, noid.

--------------------

Or, possibly plugged EGR valve? or weak valve spring?

Don't have an EGR, have a first gen B6, not even sure if second gen ones had them either.

Also, the throttle oddly enough, has to be in a very precise spot for it to start loping, just a little too high and it doesn't do it, a weak valve spring would cause it to get worse as RPMs rise I would assume. I'll record a video tomorrow or something showing what I mean.

Although I also get a loping idle when having high current draw sometimes at stoplights, with headlights on (also have aux lights wired into the low beams as well, so extra current draw)

Dead spot in the VAF or TPS maybe? with the throttle needing to be so precise?

Also, no I have never had the injectors tested, I am using the 1st gen B6 injectors, I don't know if that makes any difference on a second gen B6 ECU and VAF. I do believe the injector harness has to be modified to fit the first gen B6 injector plugs. Though there is probably no difference between the First and second gen injectors, other than color and plug shape.