87 pontiac

When I take off the oil fill cap the idle drops. Put it back on, the idle increases. These are not subtle changes, these are very noticeable...so much that the engine almost dies. Anyone have any ideas? Got me stumped.

87 bonneville 3.8 175k miles
Reply to
bonne
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How about leaving it on when the engine is running? The crankacase is under a vacuum so the emissions are dealt with. When you remove the cap, you cause a vacuum leak which will cause the symptoms indicated.

Reply to
Weird

@#@ new vehicles are closed loop systems,fuel supply oil crankcase. This is normal to comply with Emmission laws.

Rey

Reply to
Reynaud

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