novakm

Works when I disable closed loop, but not when closed loop is enabled.

730 ecm AUJP bin.
EGR is disabled
CPP is disabled, Parameters are changed so it will idle in other than cell 4, so that BLM cells will move, and patch has been done to allow highway mode. Highway mode is not enabled
VSS works fine

Only other changes are to timing and VE tables

Thanks

Grumpy

What is the enable DFCO temp. setting?.
I don't quite understand what your seeing, I don't recall C/L being a disqualifier for DFCO.

Just a thought,
You can lean out the engine, during overrun by just using the VE table, and for some apps that works out better.

novakm

Grumpy,

I like the lean out the overrun idea. I'll just need to be careful not to go too far and have an engine that dies when coasting.

I'm gonna still keep trying to get DFCO to work too. I can't shake the feeling that whatever is keeping that from working is affecting other things also.

I'll post if I figure it out

Thanks

Stevie

I've been wondering the same thing re DFCO on my setup. It appears to me that in the AUJP, DFCO isn't enabled till the MAP goes below 20kpa. The lowest I have seen is 23kpa and thats with a pretty agressive downshift at highway speed. So now I'm wondering if I have a vacuum leak, or is this another one of those GM settings that is pretty worthless?

LBSZ28BLOWN

I'm runing the aujp.bin and it works fine.
when I let of the throttle at highway speed or downshift my automatic my inj. pws drop to o.o and my timing drops to 0deg
and my WBO2 is at an AFR of 25 to 1

It will stay in DFCO until a MAP above 30kpa or an RPM below 1400.

I have made some changes to the DFCO stuff and many changes to the chip all over do to my mods.

Stevie

What MAP do you typically get when letting off the gas at hiway speed??

LBSZ28BLOWN

I looked at some data logs.
It goes into DFCO at a KPA of 25 or less.
It also goes to a BLM cell of 3 or 2.
INJ go to o.o PW
Spark advance goes to o.o deg.
O2 (mv) drop to .004


It goes out of DFCO at 30KPA
and everything goes back to normal slowly by 40kpa
the INJ PW at 31KPA is .9PW
at 40 kpa 1.4PW
at 50 KPA 1.7

The DFCO settings I have in my chip aujp.bin:
DFCO Map enable-------25KPA
DFCO Map disable-------35KPA
DFCO RPM enable-------1300rpm
DFCO RPM disable--------800rpm
DFCO time between cutouts 2.00sec

Grumpy

Just for grins, I went out and did a few chips playing with some DFCO variables, and min idle settings.

As far as the MAP signal in overrun goes, you do want a min amount of throttle opening. FWIW, everything I have has a min idle speed of 650 RPM.

You also want a min amount of Throttle Follower. Again, this forces a min K/Pa reading during over run.

Might also double check the DFCO enable temp setting. oem was 152dF, on mine.

In the 20 K/Pa column over 1600 RPM I have 15d timing.
25 K/Pa is 25d timing.

If you have the VE table correct, there shouldn't be a stalling problem. Since there is a min MPH for all the DFCOs strategies that I've seen.

LBSZ28BLOWN

Stevie, wrote:
I read in another thread (which I cant find now) that you said causing TCC to remain locked when coasting added a mpg or so. Why is this? The only thing I can see is keeping it locked will lower the MAP while coasting and cause you to spend more time in DFCO. Is that it? If that is the case, then in the $8d there is a location which unlocks when TPS is greater than the entry (0312). So I should change it to 0. But then I noticed another flag which unlocks the TCC when in DFCO (0018). Gotta fix that one also? (assuming I do want DFCO which I do for now) Am I on track here?


Yes, one of the changes I made was to the TCC and havind it not unlock on decell.
Look Here
https://www.thirdgen.org/techbb2/sho...hreadid=143093

novakm

Enable is set to 0df, 25kpa. I just checked some logs. I very seldom get into <25kpa, so that's probably why it's not working.

The thing I do not understand is why does it work in open loop?
Maybe open loop keeps the IAC closed more or something like that?

Grumpy

At this rate, I'd say that's probable.

You might try playing with the Throttle Follower stuff just for grins.