NZvortex

I searched for this issue and couldnt think of enough keywords to get an exact match to maybe something similar so...

every morning i get in the car, from a cold start, the RPM will initially jump to 1500 as expected and pause for a split nano second then jump again to range around 1800 - 2k before settling down to 1K.

This is a 2012 i4 with 9k miles.

Here is the video which unfortumately i didnt take on a cold start. From cold start the issue is more severe and the jump is quicker upon start, it sounds way more harsh and jumps higher in RPM to the range i said more towards 2k. Here on the warm start it comes back down to 1500 and jumps again. You get the idea.

Thanks for any insight whether this be normal or not.

cris_crozz

if we could see how the cold start "jump" looks like? please?
from the top of my head, what i can think of is automatic fuel enrichment... engines with carburators use choke. fuel injected engines don't, but the ecu + various sensors when detected the engine is cold richens the fuel mixture thus you get a jump... once the engine warms up, it automatically leans the fuel mix.
so... without seeing your "cold start" video, i would say the description sounds normal.

potmilkz

right before you try to start the car again, disconnect battery, and let the car reset.. this will calibrate itself again. hopefully that would work.

NZvortex

Thanks. Ill do the cold start tomorrow AM.

NZvortex

Oops! I had posted this issue before and ppl replied saying it was normal as they have experienced too. Wonder what the actual cause it though...

cris_crozz

Automatic "choke".
That's if you don't like "Automatic fuel enrichment"