Look at the MAF tables in a graph. Think of it like this: Above the line is air, below the line is fuel. If you decrease the grams/sec you are decreasing fuel. If you increase the grams/sec you are adding fuel.

When you data log look at the grams/sec and corresponding BLM. If for instance your BLM is 130 at 12 grams/sec, divide 130 by 128 and multiply the result times the value in the MAF table. In this case you would change 12 to 12.19. Do this throughout all the tables. It's time consuming but it works.

 

Okay but I'm still a little confused.

What do "Counts" mean?

There are 3 things in the data log, MAF, BLM, and RPM, where does RPM come in to play during tuning?

And the MAF only displays 24, 48, 72, 96, 120, 144, 168, 192, and 216.

I'm using WinALDL to data log.

Thanks!

 

So I'm just going to use this as an example, this was from one of my data logs. Anyway, is this how I should be doing it?

Let's say I want to change MAF 24 at 3200 RPMs. The BLM for that one is 138.6.

So I would go into my MAF tables and go under Mass Air Flow Table #2 (523-768) in the STOCK tune and change the 544 Counts from 24.94 to 27.00? Is that correct?

 

Don't worry about counts or RPM. This will be much easier if you data log with Tuner Pro. Trust me. I've been there.

 

Gotcha. Now do I have to find the exact MAF number in the data log or can I round it up or down to the nearest number?

 

First, export the data log as a .csv format. You can then read the file in Microsoft Excel. I open the file in Excel and then sort on the MAF column. Then, for example I will average the BLMs for all the MAF readings in the 12's. I use the average to calculate the new grams/sec number and enter that in the MAF table. When you've done that for a number of points in the table, look at it in graph view and smooth the lines. Then drive, data log and repeat until you are happy.

 

I don't understand what you mean when you say smooth the lines. Could you elaborate?

Thanks a lot this information is very insightful.

 

MAF Table 1 should look like a curve. It should be a smooth curve. The other tables should be more like lines and fairly straight. So if you have points that seem to stray from the line or curve, just move those points so they conform.

 

Could you post an example?

Also how many data logs does it usually take before it's complete?

Thanks!

 

Do you have a wideband O2 meter? If not get one.
What do you have your hot start to closed loop set at?

 

It should be fairly obvious when you start making changes. It's hard to say how many times. Keep in mind that when dealing with MAF numbers small changes are better. When you find yourself going from rich to lean to rich, it probably means you're really close and you can stop worrying.

I don't think I'll ever be done tuning.

 

Yes. And do you mean open loop? The AFR in hot open loop should be around 13.25:1.

Oh boy. I don't want to tune forever. I'd like to finish it this week so I can get to the dyno.

I think I'd be happy with 123-133 BLMs.

 

[QUOTE=DanielRicany;1588072754]Yes. And do you mean open loop? The AFR in hot open loop should be around 13.25:1.

There are 3 timers that set the amount of time the ecm waits before going into closed loop based on temp.
Why do you care about open loop? It shouldn't be too long before your in closed loop. Especially when the engine is hot.

 

[QUOTE=dave_85;1588072973]300 seconds when cold
206 seconds when warm
100 seconds when hot

Those are all a long time to wait. Especially when I need to go somewhere and I do a cold start. Sometimes I don't have 5 minutes to wait before I can leave.

 

[QUOTE=DanielRicany;1588073035]Change them! Are you running your ecm off of your wideband? If so use the time your WB takes to be accurate. I use a zt2 and if I remember correctly it's 45 sec cold.

 

Something is way wrong here. 19:1 is very lean. 10:1 will burn eyes, not 19:1. Are you reDing things correctly?

 

Yes. Anything leaner than like 15.5:1 burns my eyes. Anything richer than like 11.5:1 burns my eyes also. They have two very distinct smells. Not to mention the garage can't vent it out fast enough even with the door open.

 

I forgot to ask. What fuel pressure should I be at when tuning this? Right now I'm at 43.5 PSI.

 

Daniel,
The reason you are running at 11 to 11.5 AFR is that you are targeting 41% additional fuel enrichment when the car is warm when you start it in open loop. 14.7 is the stoich AFR and the 41% means you are targeting 14.7/1.41 or 10.42 AFR. Since the car is giving you 11 to 11.5 AFR lets average this to 11.25 it means something in your tune is off slightly. I would not worry about that too much I would just take it into account when you set the open loop fuel table. To fix this problem this is what I would do.

I would determine the error you are getting from actual AFR to commanded error. In this case you are commanding 10.42 and getting 11.25 so the error is 10.42/11.25 or .926 error.

Next determine the fuel addition you want which is your desired AFR of 13.25, to do this take 13.25/14.7 which is .901

We now need to compensate for your error between desired and actual AFR so we take .901 x .926 which was the previously determined error this gives us .834 this number is the total amount of fuel addition you should try adding to your fuel table. (14.7*.834 means we are targeting a 12.26 AFR but this is because I am compensating for a slight error in the tune)

Now we need to get you a number you can add to your open loop fuel table and this is how you get that number take 1-.834 which gives you .166 which is 16.6% round that to 17% or 17. That is the number you will add to you open loop fuel table and it should give you an open loop AFR of 13.25 with your current tune.

 

What do I do after I adjust the lines? Data log and then correct for it or just leave it alone after that? I predict I will be done tuning the MAF tables tomorrow. Although I was not able to get more than 160 gms/sec on my data logs. Do I need to worry about tuning above 160 gms/sec or can I sort of make the line in the graph follow the previous one?

Thanks