Lean transition into PE and lean spot during WOT

[Niemer]

Nope, seems like there isn't anything that can be done other than running open loop, disabling PE, and modifying your fueling tables for enrichment in the load area.

[BMWMD82]

Nope, seems like there isn't anything that can be done other than running open loop, disabling PE, and modifying your fueling tables for enrichment in the load area.

Do the open loop gain tables have an effect when in PE mode? Thought I remembered reading that they did. Not that it likely has anything to do with this issue, but figured I'd ask.

[schpenxel]

Do the open loop gain tables have an effect when in PE mode? Thought I remembered reading that they did. Not that it likely has anything to do with this issue, but figured I'd ask.

My understanding is they are an additional multiplier used when calculating commanded lambda while in open loop. They can richen (or lean I suppose) things up based on IVT's, injector temp, etc.

I believe it's basically all of the "open loop" and "open loop gain" tables multiplied together x PE EQ ratio = "total" EQ ratio. Then 1 / total EQ ratio = commanded lambda.

Without testing I can't be 100% sure..but I'm fairly certain that is how it works while in open loop (including PE I would suspect)

[griffincox]

My understanding is they are an additional multiplier used when calculating commanded lambda while in open loop. They can richen (or lean I suppose) things up based on IVT's, injector temp, etc.

I believe it's basically all of the "open loop" and "open loop gain" tables multiplied together x PE EQ ratio = "total" EQ ratio. Then 1 / total EQ ratio = commanded lambda.

Without testing I can't be 100% sure..but I'm fairly certain that is how it works while in open loop (including PE I would suspect)

I wish that this was the case, but everything I have read indicates that the "open loop" tables are only used during cold start (or in open loop operation where closed loop has been disabled). Once ECM commands closed loop during warm up these tables are never used again until the engine is stopped.

[Higgs Boson]

It only chooses the richer mixture from all the tables, which is always PE (as long as the criteria is met) unless you messed it up. When PE criteria is not met, it will choose from the open loop tables unless it meets closed loop criteria, in which case it will be stoich. If your MAF/VE table(s) are off then you will not get the AF ratio commanded in the open loop tables.

[schpenxel]

That is interesting. I've been meaning to play around with them to see what would happen if you tried to richen things up based on IVT, etc., but it sounds like it's not quite that simple

[griffincox]

It only chooses the richer mixture from all the tables, which is always PE (as long as the criteria is met) unless you messed it up. When PE criteria is not met, it will choose from the open loop tables unless it meets closed loop criteria, in which case it will be stoich. If your MAF/VE table(s) are off then you will not get the AF ratio commanded in the open loop tables.

Is this in regard to posts #83 and #84?

If so can you expand?

I am under the impression that all of those lovely looking gain tables are for open loop only, meaning that you must completely disable closed loop, or that they are used for warmup only (open loop only).

I would love love love to have precise load based fuel control outside of closed loop, but every thing I read indicated this was a no go. The RPM based PE table was it.

[schpenxel]

Sounds like it uses whichever is richer between the open loop tables and PE ratio, when in PE. PE is obviously always richer unless you've done something drastic to the open loop tables.

[griffincox]

Sounds like it uses whichever is richer between the open loop tables and PE ratio, when in PE. PE is obviously always richer unless you've done something drastic to the open loop tables.

Again, I have heard the exact opposite. That these open loop tables are not used.

My main point of these questions is that the gain tables provide nearly infinite better fuel control that the PE table. If it actually used the richer of the two, i would discontinue use of the PE table and use the gain tables. Its annoying as hell that 3000 rpm and 100 kPa MAP and 3000 rpm and 150kPa MAP get the same EQ ratio... Just one example.

[07GTS]

i use the OL IVT table for my fueling but u need the OL gas/OL gear to suit also otherwise it will limit at the richest one, my 02's temp are maxed out so they arnt used then i have the OL IVT for cruising light load then PE for more load in n/a area and then BE for when i hit boost so 3 different fueling tables dependant on load seems to work well so far

[griffincox]

i use the OL IVT table for my fueling but u need the OL gas/OL gear to suit also otherwise it will limit at the richest one, my 02's temp are maxed out so they arnt used then i have the OL IVT for cruising light load then PE for more load in n/a area and then BE for when i hit boost so 3 different fueling tables dependant on load seems to work well so far

Are you using closed loop though?

Edit: I guess thats what you mean by 02's temp are maxed? They are not being used?

[07GTS]

yea im staying in OL all the time

[Higgs Boson]

Is this in regard to posts #83 and #84?

If so can you expand?

I am under the impression that all of those lovely looking gain tables are for open loop only, meaning that you must completely disable closed loop, or that they are used for warmup only (open loop only).

I would love love love to have precise load based fuel control outside of closed loop, but every thing I read indicated this was a no go. The RPM based PE table was it.

They are used when you are in open loop, that's correct. When are you in open loop? When you are not in closed loop.

Like I also said, these are Commanded Values. Even if you commanded 1.2 or .8 across the whole table, it doesn't matter if you are in closed loop because the O2 sensors switch you back to stoich anyways. If you have open loop forced full time (CL disabled) or if CL hasn't met criteria to enable (like I said, warm up for example) then it will go off the richer of the open loop commands.

The title of all those tables are OPEN LOOP XXXXX so "being under the impression" sounds a bit funny.

You can use these tables to command eq ratios that could be achieved when your O2 sensors aren't switching, whether you disable them or not.

[griffincox]

They are used when you are in open loop, that's correct. When are you in open loop? When you are not in closed loop.

Like I also said, these are Commanded Values. Even if you commanded 1.2 or .8 across the whole table, it doesn't matter if you are in closed loop because the O2 sensors switch you back to stoich anyways. If you have open loop forced full time (CL disabled) or if CL hasn't met criteria to enable (like I said, warm up for example) then it will go off the richer of the open loop commands.

The title of all those tables are OPEN LOOP XXXXX so "being under the impression" sounds a bit funny.

You can use these tables to command eq ratios that could be achieved when your O2 sensors aren't switching, whether you disable them or not.

I understand.

What i am trying to impress is that if you have closed loop functionality enabled, then after warm up and after closed loop operation has begun, these tables are never used again, even when entering PE/open loop. Maybe we are on the same page, but these tables are useless (except for warmup) for PE if closed loop is enabled. Which is annoying to me. I understand its an OS limitation, but still sucks.

[Higgs Boson]

I understand.

What i am trying to impress is that if you have closed loop functionality enabled, then after warm up and after closed loop operation has begun, these tables are never used again, even when entering PE/open loop. Maybe we are on the same page, but these tables are useless (except for warmup) for PE if closed loop is enabled. Which is annoying to me. I understand its an OS limitation, but still sucks.

If these tables command a richer EQ ratio than PE then you will get the richer of the two, out of the OLFA tables, cat overtemp, knock enrich, PE, etc.

[griffincox]

If these tables command a richer EQ ratio than PE then you will get the richer of the two, out of the OLFA tables, cat overtemp, knock enrich, PE, etc.

Are you 100% sure of this? I have read over the year in multiple threads that OLFA do not override PE. I am going to tinker on the tune in a few weeks and will play with this, but not holding my breath.

[Higgs Boson]

Are you 100% sure of this? I have read over the year in multiple threads that OLFA do not override PE. I am going to tinker on the tune in a few weeks and will play with this, but not holding my breath.

http://www.hptuners.com/forum/showth...ll=1#post95887

http://www.hptuners.com/forum/showth...ll=1#post82265

Probably 1000 more where those came from.

[griffincox]

http://www.hptuners.com/forum/showth...ll=1#post95887

http://www.hptuners.com/forum/showth...ll=1#post82265

Probably 1000 more where those came from.

A few posts down.

http://www.hptuners.com/forum/showth...ll=1#post82398

be prepared to lose your O2s, as this won't work in closed loop

Many want to use these tables but are not willing to give up their O2 sensors, me being one of them.

[Higgs Boson]

A few posts down.

http://www.hptuners.com/forum/showth...ll=1#post82398

be prepared to lose your O2s, as this won't work in closed loop

Many want to use these tables but are not willing to give up their O2 sensors, me being one of them.

Where did I say it works in closed loop? If you are in closed loop, like I said, the O2 sensors are switching. If they are switching, they are switching around stoich, which is always 1.00. You might want to reread post 93.

You are not in closed loop if you are in PE or warm up or any other time you don't allow/command closed loop to be active. You are in charge of your tune, not your O2 sensors.

[griffincox]

Where did I say it works in closed loop? If you are in closed loop, like I said, the O2 sensors are switching. If they are switching, they are switching around stoich, which is always 1.00. You might want to reread post 93.

You are not in closed loop if you are in PE or warm up or any other time you don't allow/command closed loop to be active. You are in charge of your tune, not your O2 sensors.

I think we are not fully understanding each other or maybe its just me. But if you want to use closed loop/O2 sensors AT ALL, then you CANNOT use these tables for PE. Even when the ECM exits closed loop for PE these tables no longer have an impact. Only in full open loop mode, O2s disabled do these function. Something in the ECM logic dictates that these tables are not used in a closed loop system even in once in PE.