camshaft overlap effect on afr at idle.

[2swe]

I think the lean readings are caused by fresh air entering exhaust during valve overlap.
the lowest map methot seems to be the way to go..

[Peter Florance]

How about a log and msq of your recent tuning session?

[kaeman]

Peter look at the datalogs dated 2016-2-7 on my posting from earlier in this thread, that is the last time I started the vehicle. I think I might have to turn up the smoothing factors get them closer to 60 or 70. to get the idle rpm easier to read.

[72bluetr6]

Check to make sure your O2 sensor is setup and calibrated.

[kaeman]

I calibrated my o2 sensors before starting the engine on the 7th, that was the first thing I figured should be ruled out, then I checked the timing to be sure that the commanded timing was being implemented, timing matched what the megasquirt said it was.... I am hoping that I will be able to work on it this coming weekend, I plan on checking that the valve train lash adjustment is correct, installing new spark plugs, blocking off the iac and increasing my smoothing factors, then see if I can get the idle stabilized.

[Peter Florance]

Peter look at the datalogs dated 2016-2-7 on my posting from earlier in this thread, that is the last time I started the vehicle. I think I might have to turn up the smoothing factors get them closer to 60 or 70. to get the idle rpm easier to read.

I think, in order to make it easier to tune, I would flatten out Idle Advance spark values to one value.

I'm thinking 30 is too much. Maybe 20 and open throttle plate a little more.

Maybe even less.

It also might be worth putting a narrow band O2 (that can handle some heat) right at collector exit to get a better idea of what is happening.

[kaeman]

I have a heated narrow band o2 sensor and a sensor bung in the header collector, what input would I use? one of the generic sensor inputs, what extra inputs would be compatible with the narrow band sensor? I guess I have some reading to do, I will check into the sensor inputs and see if I can add it on one of the extra input channels for o2 sensors. Thanks.

[kaeman]

After much frustration with an inconsistent idle, I increased the lag settings for the rpm and map signals, I was using high values on these inputs like I had used on the itb manifold, 90 to 95 (itb settings) but the new manifold and camshaft required a larger smoothing, I am at 40 for both the map and rpm inputs. With the new lag settings the engine started having a stable idle, but the exhaust smelled bad.
I was able to adjust timing and fuel until the engine idled smoothly at 1200 rpm, after getting the smooth idle, I started adjusting the injection timing table until I had the highest rpm and richest afr without changing any of the other ve or advance settings, when I got the best injector timing the engine was idling at 1400 rpm, and the bad smell in the exhaust was gone.
I adjusted the throttle blade idle stop and got the idle down to 1200 rpm, when I put the car in gear the rpm only dropped to 1050/1100.
I I turned off the engine and restarted it, with the same results, then I let it cool off enough to need warm up settings, it still started easily.
My injection timing table is now set at 265 degrees, the throttle response is very good.
I am hoping to get some tuning done in the low load/cruising area of the ve table.
I am still having issues with the idle o2 readings showing lean, but off idle the readings are correct.

2016-02-21 good idle tune_modified.msl

2016-02-21 good idle.msq

[kaeman]

Still waiting for a chance to test drive and do some manual tuning. every weekend has been raining. I am hoping to get a chance to tune the warm up curve. during the bad weather.
Now that I have the engine able to idle, should I try to reinstall the iac and see if I can get that working correctly. Will it make cold starts easier to tune? what are the acrtual benefits of using the iac, I don't have ac or anything like that. and only dropping 100 rpm going into gear doesn't seem like a bad issue. Any thoughts?

[kaeman]

finally got to do some test driving/tuning yesterday, I turned off o2 correction and manually tuned the low load cruising area of the ve table, engine runs smooth and the ve table is fairly smooth, no big pits or spikes in the map. still having problems with left bank o2 sensor readings. most of the time reads 22.4, when it randomly decides to work the o2 readings are the same as the right bank sensor that always reads. I am trying to trouble shoot the left bank o2 sensor /gauge and haven't found anything yet, checking loose wiring and possible bad grounds, or bad heater power connections. any Idea's. its an innovate dual wide band gauge system.