The engineers at Mazda are bright people, so.... - Page 3

RotoRocket · 2005-12-16 21:52:25

You guys have got to stop letting valets touch your car... they're all pure evil! Yeah, obviously. But sometimes you just don't have any choice. When I was in D.C. last summer, we stayed in a hotel that ONLY had valet parking, and there wasn't an empty parking space on the streets for miles around. What choice did I have?

12-17-2005 | 04:34 PM

#52

Krankor

Klingon Grammarian

Joined: Aug 2005

Posts: 1,204

Likes: 1

From: Bellevue, WA

Quote:

Originally Posted by Glyphon

when the car is "cold" (not up to operating temperature) it operates a higher rpm. ever notice that when you first crank the car it revs to between 2&3k rpm and then gradually settles back down to ~800rpm?

its during this initial phase, when extra gas is being pumped in to sustain the higher rpm that the flooding typically occurs. the reason that the manual states to hold the rpms at 3k for 10 seconds is because the longer the engine runs, the warmer it gets (because high rpm produce higher combustion/exhaust temperatures), and the lower the "idle" rpm becomes. so, after 10 seconds of holding the rpms at 3k, the idle rpm has dropped to far enough below this speed so that when you release the throttle, the ecu switches into DFCO (deceleration fuel cut off) and actually stops injecting fuel into the combustion chamber. when you shut the engine off while the engine is spinning down, it cuts the fuel delivery and helps to expell any excess gas that is left in the combustion chamber.

at least, that's how that i understand it. if i'm wrong, someone more knowledgable than me will correct me

Thanks large! So it's not the temperature per se, it's the-- what I would have called the "choke", although I guess that's not technically accurate anymore. So really, watching the temp guage isn't what's important, watching until the idle revs come back down to normal is what matters, yes?

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