"Basics" Confusion

[Paul Clark]

IAC re-set. Go by rpms, correct?
This, however, may vary depending upon the chip and injectors. (?)
Should I go by the IAC index instead of the rpms?
High 20's are good, correct?
Assume this is indicated by the # number and not the %. (Tlink)
Or do you go by the MAF GPS #?
When do you take the readings?
My car goes into closed loop well before it reaches operating temp.
The numbers keep changing at idle.
At present, I get the following at a temp of 165 and rmp of 875 -
IAC index 120-121# and 7 or 8%.
MAF - 6GPS.
TPS - .40, but it sometimes drops to .38.
Am I close?
Sorry so long, but I'm confused and I'm running out of paper clips doing the IAC re-set thing.
Many thanks.

 

[Paul Clark]

Forgot to ad that the throttle response is great, but the car shakes a bit at idle.
Sounds like it has a mild cam in it.

 

[scottyb]

here's the stuff

Idle rpm is controlled by chip.
IAC is not a sensor. The IAC number is the "amount of air" command that the ECM is asking for to maintain it's programmed rpm. The higher the IAC, the more the ECM is commanding air to maintain idle. When 0, the ECM is no longer controlling the low end, and idle may rise as a result of throttle blade being open.

High 20 is ok.
I shoot for 10 or just over. A change in conditions (bar pressure or temp) can make it lower on a different day. I've seen mine hit 0, but the idle wasn't riding so I'm ok with that.

Be sure your throttle body is clean. Oil or debrit around the lip of the throttle blade will make it difficult to get a constant.

All your other number appear good.

 

[Paul Clark]

Thanks.