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Old 08-17-2002, 11:49 PM
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Beav Beav is offline
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Join Date: Nov 2001
Location: Louisville, KY
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Significant Technical Input
Whoa!

Patient: "Doc, it hurts when I do this."

Doctor: "So don't do it."

The computer's programming depends on the input of many sensors. However, before it begins to decipher their readings and base its responses on them it wants everything warmed up and functioning properly. When the engine is cold it operates in 'open' loop, in other words the computer runs from a fixed set of parameters. Once the temperature and oxygen sensors (typically, this can vary slightly from one OEM to another) it will go into 'closed' loop where it will use all incoming sensor info to determine its responses.

So, all that you're probably witnessing is a bit of sub-optimal response while the computer is still in open loop. The engine doesn't have to be fully warmed up to reach closed loop, just enough for the computer to realize what's going on and respond. Some cars have better open loop programming than others and won't exhibit any/many flaws, others aren't so lucky.

If your car is up to date with spark plugs, fuel and air filters, the throttle body and idle air controller is clean and the check engine light isn't on, you're probably good to go. Just expect the foible until it's warmed up a bit and be thankful your car isn't picking you to pieces....
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