2003 Toyota Corolla with 1.8 liter four-cylinder, manual, 176K miles, no codes. I cleaned all the intake pieces I could find according to your videos but when the engine is cold it revs to 3000 for two seconds then drops to 1200 for two seconds, constantly pulsing like that until it gets warm. ONLY when the temperature outside is under 40° or so. No problems otherwise (thanks for pointing me toward a decent, long-term vehicle!).
Pretty odd. Does it throw any codes? We call this hunting in vehicle repair. The car is looking for a suitable idle rpm and cannot find it so it does this. Usually it is vacuum or fuel related.
Thanks, @cjbman.
As mentioned, no codes. I listened quite a bit for a vacuum leak and found all to be solid as far as I can see. I haven't done the cigar technique (I'm not a smoker). I was hoping for someone to recognize the symptom and clue me in.
Okay, I checked again and confirmed that my memory was bad: it pulses from 2000 RPM to 2400 when cold.
Clean the MAF sensor.
Also check/change spark plugs if it's due
Hmm. What makes you suggest that?
Did it do it before you cleaned it?
