okay, tuning a 355 with a mild cam, blm's are in line driving and such.

Hot IDLE blm's go to 160.

8 gm/s blm of 147
10 gm/s blm maxes 160
15 gm/s blm comes down some

around 24 gm/s blm is back around 128-130

should I adjust the MAF table 1 to indicate higher air flow readings?

i'm new to this, i've read the guides, not much stuff on $6E tuning.

also, on warm startup, engine reves to 1700 before coming back down to normal idle. warm IAC steps is around 25 for 180 degree where the engine was at.

 

Check for air leaks between the MAF and TB, and check for any vacuum leaks. Then see if the MAF is "gutted". Then, a faster way to the end goal may be to raise the Injector offset vs VBatt a little. Try adding 0.1ms at a time, and see if it helps. That table has more of an effect at idle and low loads.

 

How much overlap does that mild cam have? It doesn't take much at idle to fool the O2 sensor into thinking the AFR is lean.
I had to put in a CAL value in the MAP code I run to not do closed loop below a certain RPM. That is with a mild cam and -4* @ .050" of overlap.

 

You are probably not lean. The narrow band O2 sensor can not accurately read exhaust at idle if your cam has enough overlap to fool it. I have the exact same problem, and I've been working on it for over a year. My solution is going to be to buy retro roller lifters and get a roller cam. Is your cam flat tappet? If so, you may be stuck fudging like me, and the BLM is just going to hang at 160 for idle. You can still tune around the BLM being maxed at idle.

 

flat cam..

it causes real trouble when it is hot with hot air temp also, loads up...this sounds like my problem.

wonder if way to disable closed loop idle.

I guess if everything else is close, i can change max BLM / INT value to a lower...say 140 instead of 160..that should greatly improve hot idle problems.

 

No easy way to disable closed loop idle in 6E unless you can write assembly. You can cap the BLM at 140 and then adjust your MAF around idle until you get it to do what you want. You're going to be stuck doing that with a flat tappet cam that idles dirty.

 

I added some timing last night at idle and the blms came down from 160 to the 140's. Don't know if it will work for you or not,but it's worth a try.

 

How much timing are you running at idle now? I already idle at 26 degrees.

 

39 degrees

 

Wow that is a lot of idle timing. I think I'd be terrified to run that much with my 9.7:1 static compression.

 

I don't know if it's just my car or what, but the conventional doesn't seem to work. I don't have enough seat time on this tune (just down the block and back) to determine if it's ok or not, but before I changed it to 39, it was at 33.

 

Extra timing at idle WON'T damage an engine easily, so don't be afraid of it for that reason. One problem though is that it makes the engine more efficient, which can reduce INJECTOR PW to an unstable point in the linearity aspect (if you have larger injectors). Having high timing at idle, near MBT timing, can also reduce the effectiveness of idle stability spark advance algorithms from working, but I don't think $6e has that. Another problem is that snapping the throttle open from idle may allow a few really advanced sparks before it realizes the extra load, and may knock really hard.

BUT, I'm not opposed to adding plenty of idle timing to help a cam smooth out at all. It's what it needs. 39 may be a lot, but it's your engine, not mine! Try it and find out if it's acceptable.

 

Upping the timing has also helped to reduce the stinky fuel smell at idle.

 

There's a Closed Loop Rich/Lean Threshold vs. Airflow table at 046B that you can use to target a much leaner voltage at low airflows. Try targetting ~200 mV at the lowest 3 airflow entries.

It may also help to raise your target idle RPM a little.