Up and down idle when cold - Toyota Nation Forum : Toyota Car and Truck Forums

JohnO356 · 01-22-2007, 05:48 PM

2000 Corolla, I don't use this car every day. When I start the car cold, with temp around 40, the idle surges for the first 2-3 minutes and then smooths out. It idles fine after that, and has no other problems and no CEL. No strange exhaust odor. Seems minor, but don't want to let it develope into something worse. Any ideas? Thanks.

daniel2002p · 01-22-2007, 08:51 PM

I think that is the PCM putting priority on emissions over smooth running engine.... I heard that somewhere for the 9th gen'er dunno if that is the case for the 2000..... if it is this I think that is the way they work...

D

splavin90 · 01-22-2007, 09:01 PM

its normal

DarkNinja75 · 01-22-2007, 09:31 PM

The car naturally runs at a higher idle when cold. Takes a few minutes to heat up, then the idle drops back down. Nothing to worry about.

***REN69*** · 01-22-2007, 10:13 PM

Welcome to Toyota and winter. Mine idles at 2300 to warmup, then it goes down.

JohnO356 · 01-23-2007, 06:35 AM

OK, thanks. I know that the car idles faster at startup. It's the little surge I was wondering about. I'll just ignoe it.

daniel2002p · 01-23-2007, 07:11 AM

i think he means the the RMPs go up and down rapidly when idiling at cold.... not that they are just higher

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ghost_ryder35 · 01-23-2007, 08:38 AM

i'm confused, is your idle up and down spuratically (can I spell?) or is it constantly higher rpms for 2-3 minutes then the idle evens out? If it is constant then dont worry about it, however if it is spuratically then daniel2002 got some info for you

JohnO356 · 01-23-2007, 08:52 AM

As Daniel said, the idle speed rises and lowers (surges). Only lasts for a minute or two when it's first started cold. The surge isnt much- maybe 100 RPM's.

ghost_ryder35 · 01-23-2007, 08:55 AM

Quote:

Originally Posted by JohnO356

As Daniel said, the idle speed rises and lowers (surges). Only lasts for a minute or two when it's first started cold. The surge isnt much- maybe 100 RPM's.

100 rpms i wouldnt worry about. I thought you were talking from 1000 to 2500 and then back to 750 to 2300 and so on.

JohnO356 · 01-23-2007, 09:26 AM

No it's slight, but very noticeable when you are standing by the car. Not worrying about it. Thanks.

jeprox · 01-23-2007, 06:06 PM

my 03 have this particular problem and a lot of other 03+ as well.
my problem started just last year around october. start up the car cold to warm up - it will stay up around 2300 rpm or so and all of a sudden, the rpm would be jumping up n down.
it's similar to when you are revving your engine - like that. no, it's not normal.
does it hurt your car in any way, shape or form. i dont know, probably not.
did lots of research and asked around a lot, most people say it's to do with the IAC valve.
if you wish, you can try cleaning your MAF sensor to see if it helps. some people tried cleaning the coolant sensor.

for me, i chose to just leave it and live with it. i was gonna take it in to get it fixed but my warranty just ran out so i'm out of luck.

goodluck.

daniel2002p · 01-24-2007, 07:44 PM

oh 100rpm is not a big deal at all, its just the ECU trying to find a good emission rate... I thot u were saying it goes from 1000 to 2500 constatnly... I wouldnt worry about it...

D