DrowningMan

I went out to start my car this morning and something strange happened. I started it and it revved kinda high...close to 3000rpm. after it that it idled down and stared running really rough, like I had a huge cam in it....thing is...I don't. I turned it off, and then started it again. it jumped up kinda high, but not quite as high as the first time. it still ran fairly rough, but not as bad. I let it sit there and warm up a bit before I left, it still ran odd for a little down my street, but then ran normally, and has since then. It was fairly cold this morning, but its been colder and it didn't do this? any ideas? could have just been the cold? I had some problems awhile back with the front o2 sensors melting from the headers and it caused me to run pretty bad due to the A/F mixture being screwed up. I got that fixed and haven't done anything to the car since then.so....help?
Thanks,
ryan

WeatherGuy

Could be a few things - the most likely one is something got on your MAF sensors and gave bad info to the engine (were wet, wet dust, frost, . . . )

DrowningMan

Thanks for the reply. Im thinking that might be it..but i dunno. That was this morning, the car has ran fine all day with no problems, so I guess if there as something on it or whatever, its clear. I just got paranoid I guess. After spending $1700 a few months back fixing my car, I get scared id some one looks at iy wrong...

A70camaro

Did you happen to pay attention to your
oil pressure?

GM had a problem a few years ago where on cold start up the oil pressure was so high it
would pump the lifters up and make the engine run rough and other problems . Even so bad to have loss of compression in all cylinders .
Happend on Quad4 engines

What oil are you using? Anything other then 5w30
in cold weather can cause problems .

Or might have been so freakin cold that you got really deep into the PCM tables for coldstart warmup
Gotta light off those converters on cold startup
lots of fuel and high rpms will do it.