Trying to get a "behavioral" idea on startups

[clickman]

Originally Posted by stateofidleness

yea, they're due to "Secondary Air Injection" faults (I have a lingering exhaust leak). not sure why not waiting on the air pump to turn off would increase the likelihood of the CEL, but I notice the correlation between the two.

There you go. Something in the secondary air system needs to be fixed. Fix that and no more CEL, and therefore no need to "wait" at startup.

[stateofidleness]

well the fact that there's a difference in exhaust 'levels'/'mixture richness' based on "waiting" or "not waiting" implies that it might be beneficial to wait, regardless of exhaust leak or not.

the fact that it throws a CEL tells me that there's different exhaust behavior if I don't wait for the air pump to do its thing. so i'm wondering if that "non-wait" behavior is harmful to the overall health of the engine/vehicle.

[thstone]

My understanding is that the air pump and secondary air injection are emissions related, not performance related.

What seems to be happening is that there is a problem in the emissions control system and you get a CEL if you try to drive off while the air pump is still operating to avoid the CEL. You've found that if you wait until the air pump stops, then the likelihood of a CEL is much less.

The bottom line is that the emissions system needs investigation/repair. Then there will be no reason why you can't drive with the air pump operating.

[jbs986]

Originally Posted by thstone

My understanding is that the air pump and secondary air injection are emissions related, not performance related.

What seems to be happening is that there is a problem in the emissions control system and you get a CEL if you try to drive off while the air pump is still operating to avoid the CEL. You've found that if you wait until the air pump stops, then the likelihood of a CEL is much less.

The bottom line is that the emissions system needs investigation/repair. Then there will be no reason why you can't drive with the air pump operating.

+ 1 sounds like your secondary air system, here is a link to repair it. good luck.
www.nutrod.com/nutrod/home.html
just click on (secondary air system)