AFRs on idle

[pezza]

Hi all,

I just wondered what kind of AFR's you would expect to see on idle on both hot and cold engines.

The warmer the car is I can see AFR's creeping up slowly from 14.5 normally fluctuating to 15.2 but on some occassions it seems to get to 18s at which point the car is hunting and has uneven idle. Seems to suggest possible air leak maybe... but I am also pulling the dreaded TPS 41 code too (I think thats open circuit).

I have spoken to a couple of other members and it seems others have seen similar, encompassing issues with o2 sensors TPS, Idle stepper motor and possible leaks...

I also wondered if there were any guides on setting up TPS..

Cheers

[Nick Mann]

It should be bouncing around between mid 14's and low 15's on a stock car running well. It shouldn't see high 15's, let alone 18's!

[peter thomson]

14.6 to 14.8 on my one at idle. Anything else and something isn't quite right

[pezza]

Cheers for the feedback I have a few avenues to inestigate now....

On the move values are as expected ranging from high 9s to 13.9 14.2 on v light throttle/cruise so am hoping that the probolem is ioslated to idle only.

[swinks]

Got similar issue, but more likely steady 15-16 and jumping to 18's when I had disconnected rubber big pipe behind a MAF

[adaxo]

13s on cold start and between 14-15 after 2 mins, and all the time when hot on idle

[Eurospec]

That sounds like an air leak mate. Post maf pre throttle body probably (but not definately!)

Cheers,

Ben.

[Kenneth]

This symptom also seems to appear with the ECU in open loop at idle.

[pezza]

will keep a hunting for this, thanks for the input guys...