I have been dialing in my a/f for a bit now and discovered I was going about it wrong.. **facepalm** FINALLY doing it the right way and nailed nearly every cell on 20x18 to 3% or less difference on the rich side, I switched to closed loop and then it went potato... Crap. Not bad, but hesitation and sluggishness; kinda like trying to jog uphill with a backpack on.. Anywho, I disabled closed loop and went back to open loop and it's smoother than Rick James after a fifth of Hennessy.. Any reasons I shouldn't just stay in open loop?

 

What EMS you using to tune? Are you using your wideband or stock o2 for closed loop fueling correction?

 

My bad.. Neptune and Innovate LC-2 WB

 

Does your wb use a 0-5v reference for closed loop or does it have a narrow band simulation? If you're using 0-5v then you need to make sure you click the "invert closed loop operation" and you also need to set your "closed loop corrections" to about -10% and +10%. As well as make sure your target voltage is set correctly based on your target afr. Maybe take a screen shot of your closed loop option tab.

 

Yeah, I watched my datalog for that run to catch my 13.0 target voltage. The entry for target under closed loop settings was .51v.. NOWHERE near my target range. Target range would be 1.87v for this setting. That may make a HUGE difference really. I'll see about that screen shot.

 

Here's the SS of my settings. May or may not still be jacked lol

 

What pin on the ecu do you have you wb wired to? You have the stock o2 sensor wire selected. Also you should disable closed loop closer to 700mbar. Set you min max to -10 and +10, and 75 coolant temp is a little early to start closed loop as you ect fuel comp should still be adding fuel until it get a little warmer. I'd wait until at least 100 coolant temp or warmer to start closed loop, you want a slightly rich idle for cold start.

 

I do believe it's on the stock wire. I chose D14 over D10 as I didn't really think I would need all 5 volts and so far, I have not. It has done well monitoring 3.78 volts up to the present. Any time I am ever in that range is only on fuel cut at decel. You're helping tons right now!!

 

Ok that makes sense now. Yeah try entering what I suggested above and let us know how it works for you. Should run a lot better. Glad I'm able to help you out man

 

All fixed up now! I'm still at work til 11pm. I'll log my run and watch it when I get home; about a good 20 minute drive. To the question of which setting though, is there anything really detrimental about running full time in open loop? I understand it's commonplace to set your targets and start tuning in OL until you're as close to them as you can get, then go CL and let the ECU work its magic. I would think the only real con to full time open loop would be having to deal with crappy weather conditions and wonky engine behavior since the ECU isn't making the corrections?

 

There is absolutely nothing wrong with running open loop all the time as long as it's tuned properly. You will likely end up spending more time dialing in all the fuel compensations for different weather conditions. I've found from messing with my own cars over the years that you will get the biggest variations in afr at idle, I was never able to get it perfect all the time. Now I just get idle and part throttle tuned as close as possible, enable closed loop and move on to tuning the fun stuff like boost lol.

 

I could see that being an issue in extreme cases. When I really buckled down and started my open tune, it was sunny and 74, not a cloud in the sky and low humidity. Today was cold and rainy as ****, however, I was running pretty smoothly still. I have allotted myself plenty of time to get the hang of tuning before playing with boost, but that is the plan

 

Thanks again a million times over! I ran so much smoother with these couple adjustments! When I viewed my log, I see I need to make adjustments again.. I am lean past 700mbar lol. couple cells 13% or less, most are 10 or less. Think i'm just gonna knock out all cells over or under 10% as I don't feel I would ever be able to tune to a zero. Looking at my graph though, it looks like 3rd grade art project. Any tips on the best way to interpolate?

 

To determine if a cell need adjustment you need to "drive in the center of the cell" meaning try to hold that exact load and rpm with no change in tps. Anytime your tps is changing you will not get an accurate reading on your log because of tps tip in/out. What I do from the get go is view my fuel map in 2d and manually smooth out the graph (basically removing and large spikes or dips) the I begin tuning making large changes, then coming back and fine tuning it. I find this makes it easier to see what is actually happening, this isn't the only way to do it, but it makes it easier for me. I always keep the 2d map showing to be sure the changes I'm making look smooth and even for the most part. I don't usually use the interpolation function much. One of the best things that really helped me speed up the tuning process was wiring in an toggle switch to the dash for on board logging, basically all I have to do is flip the switch and it will start recording a data log and automatically save it when I turn it off. That way I drive around and find the rich/lean spots, hold a constant tps, rpm, & load then start a log. This makes it very easy to get actual accurate data to make proper changes with. Your fuel map should look nice and smooth without sharp dips or spikes, with evenly spaced lines for the most part when your done.

 

If your open loop tune is squared away you can run full time open loop with no issues. (Many people do). The only problem is if the tuner is not up to the task of reliably setting a tune for all conceivable weather conditions and so fourth the tune could run better/worse with the seasons of the year. Also, you can suffer fuel mileage losses that are fairly significant with full time open loop if it is just rich on the side of caution vs a closed loop system monitoring the ratio. Lastly, the issue comes down to your state emissions/inspection routine. Your car will likely not pass a state emissions inspection where required running full time open loop. If this isn't a problem for your state then disregard.

 

I have no smog inspections where I am.. Hell, I have no any vehicle inspections where I am lol. I will have to see where my fuel economy will sit now that my closed loop should be properly operational. I was at 400 miles per tank pre mods, after mods and playing with the tune, I dropped to about 280 per tank, BUT, I was also not adjusting my tables correctly.

 

Sounds like I may need to take it on a longer drive then? I have a few open areas on my way to and from work for decent, mostly steady driving and a couple WOT bursts. Nothing spectacular though. Sounds like I need some good highway time!

 

Or a steady state dyno

 

After close to a 45 minute run in city and highway conditions, I ended up with the following.. It looks a lot better now than it did, but still not quite where I want it. I know i'll have to adjust my open table since i'm still pretty rich below 700mbar. Now it's getting fun!

 

I'd love to get some dyno time but the nearest tuner to me does not do imports. The next one that does is over 3 hours away and charges 120 bucks per hour with a 3 hour minimum. I'm in no hurry to spend that kind of money for a mild NA tune. I purchase nothing but clear premium fuel (93 octane without ethanol), and have used no more than 35 deg advanced ignition in any tune I've worked with. Mechanical timing is dead on, base timing is a perfect 16* BTDC. I feel safe saying that i'm no more in danger of blowing anything up than Oprah is likely to decline cupcakes.