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Discussion Starter #1
I use my car mainly for short trips around town, with an occasional harder run on the freeway. If I drive the car a short distance after a cold start, say a mile or less, then turn the car off for a while, upon restart it runs very poorly for the first 30 seconds or so. Symptoms are as follows; it starts and idles fine, but under acceleration it stumbles, bucks (sometimes fairly violently), and has no power. After a brief while, it feels like it "clears its throat", and then runs fine for the rest of the trip. If the car gets fully warmed up due to a longer initial run, it does not exhibit any poor running symptoms upon a restart. Car is not throwing any codes. Thoughts?
 

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For starters, go beat on it for a while like it should be driven. I mean hard, high revving miles for a good 20-30 minutes. Then finish off with a short highway cruise. See if the problem is any different the next day.

There are a litany of potential areas that could cause your problem.
 

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The "potential things" list is large, but you did start one of my favorite types of threads, make a pure guess with vague information, I get to go second! Temp sensor somewhere or the Ebox fan. It would seem your car is defaulting to a enriched cycle that does not suit the actual temperature of the car.
 

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Discussion Starter #4
The "potential things" list is large, but you did start one of my favorite types of threads, make a pure guess with vague information, I get to go second! Temp sensor somewhere or the Ebox fan. It would seem your car is defaulting to a enriched cycle that does not suit the actual temperature of the car.
Truth be told, I was hoping to hear from you and Technician117, but was also hoping the hear something along the lines of "Oh, those are classic symptoms of a bad "XYZ", replace it and your problem will be solved". Not going to be that easy I guess. I agree that the car acts like it is running very rich during the rough running period. Wish I could provide less vague information, but as I said, the car is not throwing any codes. Probably the only additional information I can add is I recently replaced the thermostat, and the problem is not intermittent, it will do it everytime it is shut off after a brief (less than 5 minute) run followed by a restart.
 

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I’d start with the basics. How fresh is your fuel filter? I say this because when I bought my ‘02 at approximately 120k miles I found the fuel filter original to the car. Changing that and spark plugs were first steps in my three years of ownership. You need Peake reader or equivalent to check for fault codes, as there’s a number of things that could be causing the issue. Air filters good? MAFs? Again, start with easiest and cheapest components first.
 

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That is what makes these problems fun, figuring out what is going on. First step unplug the mafs and drive it that way for a bit. See if the car behaves different.
 

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Any updates?
 

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Discussion Starter #8
No, the car is in Florida and I, (regrettably) am in New Jersey for several weeks.
 

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i had those symptoms, after i changed all 4 o2 sensors no more issues had 150k on them.
That is the most likely suspect and test 2 for me after I confirm MAFs. The next step is to unplug the front two and see what behavior change you get. If I replace the fronts I also replace the rears.
 

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I'd start with checking the coolant temp, via the cluster. it should be plausible for how long the car sat in relation to how hot it was when you shut it off. It may think it's colder than or warmer than it is
 

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I'd been having this exact same problem on my car w/84k miles. I unplugged the MAFs and went for a short test drive which gave me confidence to replace them as first remedy. Installed the new MAFs last week and all seems normal again.
 
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