Open loop or semi open loop still?

[louis]

Hello.

It was found that I had setup a semi open loop and I believe I made all the right changes to bring it into full open loop speed density.

For some reason when I decelerate or even just let my foot off the gas I go rich. I give it throttle and I see stoich again.
I started to adjust the main ve table but then noticed it takes fuels out of the deceleration cells constantly till I am almost at 0 in those cells and it still stays rich no matter how much I adjust them.

I started to back link the scan tool cells to see what it is using and I see in the spark etc table it s using only the 140c row of data to adjust the dyncyl air. I had my temp in F and changed it to C thinking this could be the reason that cell tracks only in the 140C row only but that didnt change it, The engine runs in 90C constantly

I see the same thing happening in coolant temp spark multiplier using same 140C row only. My intake air temp is in C also and same thing with spark iat table.

I am now looking at the B3647 and I see it is only using mostly one column in the 20kpa... What am I doing wrong and is this the reason for the decel fuel to continuously take out fuel?

Thanks

Louis

[louis]

I forgot to add these in

Thanks

Louis

[Chevy366]

You should be in open loop with the setting you have .
Looked like you have DFCO temp correct .
I don't agree with the tutorial in the {B3647} area I used .99 in all but the last two cells as it show in the COS3 tutorial , the way they have it now it look as if you are using {B3647} to control a PE like state .
Also the {A0008} settings are strange , I have found that {A0014} in fact has more influence over cold start fueling than {A0008} ({A0014} multiplies the VE , and {A0008} multiplies the Commanded Fuel {B3647}) , thus I leave both at 1.000 or {A0014} remains at 1.000 from 194*F and above 194*F , anything below 194*F I go above 1.000 to compensate for cold start up AFR .
{B4101-02-03-04} can be zeroed , read that they can have a influence on the {B3647} table working correctly .
I would not take what I say to heart , these are just my observations and am sure not totally correct , but none the less they are something to get started with .
What I understand the {B3647} when the AutoVE process is happening it is just BEN factors so richer cells in the {B3647} table don't hurt , when AutoVEing you are just shooting for a value of 100% thus the 1.00 so .95 is 95% of the value and needs to be corrected .
Maybe someone much better at this will chime in and clarify more for you .

[dc_justin]

Also the {A0008} settings are strange , I have found that {A0014} in fact has more influence over cold start fueling than {A0008} ({A0014} multiplies the VE , and {A0008} multiplies the Commanded Fuel {B3647}) , thus I leave both at 1.000 or {A0014} remains at 1.000 from 194*F and above 194*F , anything below 194*F I go above 1.000 to compensate for cold start up AFR .

One thing to note:

A0014 will affect the fueling calculations and should be used to keep your AFR in line with IAT changes. A0008 alters your commanded AFR. Your best option is to nail down VE table (or MAF calibration) then determine what type of values are needed in A0014 to keep that AFR in line, then set A0008 to what you'd like your warmup AFR to be.

[Chevy366]

Make sure in the scan tool that the values are the same , Imperial , Metric as the PIDs .

[louis]

Thank you for all the info. I am going to apply this now and take it for a spin.

I will keep all posted.

Thanks

Louis

[louis]

Hello.

After reading all that is here I am not sure if I explained my problem good enough.

I understand the A008 and A0014 functions a lot better now but twin intercoolers I really dont see much change in the intake temp while driving normal. This is the problem. When I drive normal is when I have the problem.

Temps do not change anywhere while this is happening. While driving speed limit I see stoich. As soon as I let off the throttle I see 11 and 12s while off the throttle or any time the engine goes back down to idle.

If someone could look at my map I added here previously where the cells inder 15-approx 35 kpa are constantly being reported as needing less fuel till the numbers get to almost 0 in the cells. Im sure it would go a lot lower then 0 but I keep trying to smooth that out only to see that it wont change the fact it reports rich there.

In open loop speed density I was under the impression that dfco doesnt come into play? What can be causing fuel to be constantly rich on decel even after map is corrected. The cells report approx .85 to be taken out of those cells every run.

Thanks

Louis

[BlackGMC]

Have you tried disabling B4108 -STFT idle trims, mine was doing the same thing while I was trying to AutoVE, disabling this helped.

[Chevy366]

Can't say about the rich off pedal fueling but DFCO is turned off when AutoVEing to keep it from going lean when you go off pedal fueling , that way smother fueling transition from off pedal to on .

[dc_justin]

If someone could look at my map I added here previously where the cells inder 15-approx 35 kpa are constantly being reported as needing less fuel till the numbers get to almost 0 in the cells. Im sure it would go a lot lower then 0 but I keep trying to smooth that out only to see that it wont change the fact it reports rich there.

In open loop speed density I was under the impression that dfco doesnt come into play? What can be causing fuel to be constantly rich on decel even after map is corrected. The cells report approx .85 to be taken out of those cells every run.

Thanks

Louis

What injectors are you using?

[louis]

Hello gentlemen.

Yes stft and ltft are off. I have 75 lb inj and I used the exact same setup last year and ran excellent. I just added a better blck to the same mods and have only 200 miles on it so far.

I am running f1-c procharger 1250 hp, lsx intake, 90 mil throttle body, callies crank and rods, -32 cc mahle blower race pistons, dart ls1 cnc heads, fuel pump with voltage enhanced, dbl roller timing chain and gears, Ram 1000 hp dual clutch and I wont mention the 500 hp nitrous shot on top of this because I wont touch that till I get a good tune first.

Is there any way for me to follow which tables the program is using? I do run the scan and link it to the tuner but then I have to click on hundreds of links to see which it is using which the scan log is running.

What else would be constantly adding fuel on decel?

Thanks

Louis

[dc_justin]

It's not uncommon for large injectors to be rich on decel with even a very minor error in your injector tables. Check tables B3701, B4005, B4003 and B4004. B3701 would be my first step in correcting this.

[Chevy366]

Cylinder bore larger , air mass may be off ?
{B0104} ?

[louis]

Hello.

Regarding these tables Check tables B3701, B4005, B4003 and B4004. B3701 is there a formula to derive at this? I hate to mess with these blind and just guess what to do. I do know I ran the exact same motor last year and it didnt have this problem at all. I really hate to mess with any setting until I understand them completely. Is there any info out there I could read up on about say what size injectors should have a certain pulse width?

As far as my ve table being off and causing this I have tried every combination of ve tuning I could do and still rich when letting off the gas. I am thinking now the only way I can fix this is going closed loop and work the dfco.

What do you suggest?

cylinder bore was .030 over last years engine but air mass for a 408 is correct. 836 for a 400 c.i. bored .030

I am not driving this now till I figure out some sort of equation or proper adjustment I should make. Any suggestions?

Thanks

Louis

[dc_justin]

If your injectors come with turn-on time and offset information, then you can use that to guide your adjustments to those tables. Do you have that information?

[louis]

Hello.

No I do not have that info and will try to get a hold of the guy who bought them so I know what brand etc.

If I cant find I could start by using any 75lb inj info?

Thanks

Louis