Idle Speed?

[ManBearPig]

Its because of the VCT trying to balance stability and fuel consumption.

Base idle in gear is 645, in neutral its 650.
You then have a MAX idle based on coolant temp.
a table based on gear and coolant temp.
then you have minimum tables for neutral and drive/in gear vs VCT.

Watch your intake cam angle and you'll see it going from 0 up to 30. At 0 it will idle higher and be more stable(extra load from AC, alternator, gear engagement, ect.), at 30 it will idle lower and be more fuel efficient when it can.

This is the kind of info I was hoping for. Does the in gear vs neutral only apply to auto trans? But it sounds like it is acceptable to idle higher under certain conditions? It also seems to do different things when it knows the clutch pedal is depressed?

Sponsored

 

[markmurfie]

The autos have a base idle of 600 in gear and 650 in park/neutral.

The MAX idle based on coolant temperature is pretty much the same unless you are in less than 15*f then the autos can idle at a higher RPM.
There is no table based on gears as P/n and in gear is all the autos need. This is the table it uses when the clutch is in. 1st is 700, reverse is 675, higher gears are 650.
Then they have the same min in neutral based on VCT
in gear the autos can get down to 590 where the manual only will go to 640.