Need some advice on low IAM

[gotbeef]

Originally Posted by nikitopo

Don't mod your car before you solve the AIM issue. Check also if you have the same behavior with stock tune.

All of this testing is done on stock tune with initial IAM = 1.

IAM is actually slightly higher on stage 1 since I've adjusted timing based on knock behavior.

[gotbeef]

Originally Posted by Phantobe

Even on the stock tune your IAM will drop (stock starts @ .70) 91 octane sucks, this car was meant to run 93 for sure...

I adjusted my timing tables & IAT tables a bit but on occasion my IAM still drops below 1.

I only fill up with Chevron & this yields the best results.

I think when IAM drops below 1, people make a bigger deal out of it that it actually is. Ideally it should be at 1, if you get a custom tune. Running an OTS tune will generally not provide this, to my (basic) knowledge all the ECU is doing correcting the timing for the fueling conditions. I don't think your engine has a higher chance to blow up if its below 1, just means your ecu is doing more work.

I'm shooting for IAM of 0.8 or better right now... I'm stuck in the 0.3 - 0.6 at best so I'm losing lot of power.

I'm not too worried about engine blowing up on stock tune but I'm just trying to get the power I paid for...

[nikitopo]

Yes you lose a lot of power. Unfortunately, our engines are very sensitive to fuel quality. The stock tune was based with the assumption of the higher quality fuel. Probably Japan quality.

[gotbeef]

Originally Posted by nikitopo

Yes you lose a lot of power. Unfortunately, our engines are very sensitive to fuel quality. The stock tune was based with the assumption of the higher quality fuel. Probably Japan quality.

I'm fully aware of the car being tuned for better fuel and that I shouldn't expect perfect IAM.

The issue here is that my IAM is noticeably lower than other California cars. 0.3 IAM isn't what most people see with good fuel. So I'm trying to figure out why or at least find out if others had the same issue and how they solved it. So far it doesn't seem like others have seen this and maybe my engine is particularly bad. Most stories I read are IAM of 0.7 or better that improved to closer to 1 after better fuel.

[Phantobe]

Originally Posted by gotbeef

I'm fully aware of the car being tuned for better fuel and that I shouldn't expect perfect IAM.

The issue here is that my IAM is noticeably lower than other California cars. 0.3 IAM isn't what most people see with good fuel. So I'm trying to figure out why or at least find out if others had the same issue and how they solved it. So far it doesn't seem like others have seen this and maybe my engine is particularly bad. Most stories I read are IAM of 0.7 or better that improved to closer to 1 after better fuel.

Mine has dropped that low in some cases on the stock OTS tune, and all I had was a catback no sign of leaks. LTFT & STFT were normal.

I can try to find my timing tables later when I get home but I had to do a lot of tweaking to the OTS tunes to keep my IAM above .80 or so.

My suggestion would be to re-flash, let the ECU learn a bit. Make sure you're running some good fuel, Shell or Chevron would be my recommendation. Then start logging and see under what conditions your ECU is pulling timing.

[MisterSheep]

I've been having the same issue lately. Keep in mind I'm on the stage1 map. I went on a drive with some of the other 86 members in the area and noticed my IAM was dropping from 1. At first I was lightly worried because I've never seen IAM drop below 1 before, even while I was at the track during 100degree weather. During the drive it was down in the .80's area and then after our first destination we all stopped, had lunch, then went on our way again. After that stop IAM stayed at 1 the whole time up Mt. Hamilton. It wasn't until our drive down did I see my IAM go down to .68. After that I pumped 2 gallon of some 100 octane fuel into the car. It did not go up much until I reflashed and took it easy. Went on another long freeway drive this weekend and noticed it go below .9 yet again. Curious to see how going through some more tanks should affect the IAM.

[Kodename47]

Do people realise that IAM does not start increasing unless you're above a certain load? It won't usually increase under cruising.

[steve99]

As @Kodename47 said IAM does not reset instantly.

quick IAM reset (assuming their is not a lot of knock)

do 2 or 3 light steady throttle runs in 2nd gear, slight uphill grade is good. go from 2000 to about 5500 rpm. Use only about 20% throttle or so, 3 steady runs like that should reset iam assuming their is no big quantities of knock