Nistune Forums

Can you have a look at the enrichment tables? The weather here is getting colder here and it seems like the tables are not acting the way they should be.
I'm warming up way too lean and I can't seem to change it. Here are some of my observations.

I Used the Temp Conv Tables to simulate various temperature ranges while making changes to the enrichment tables to see how the AFR's respond. (that way I did not have to wait for the engine to completely cool or an entire day for another cold morning)

Often times making changes to Enrich (Warm Crank) changes Temp Enrich too and Vise versa.

Enrich (Warm Crank) Has No effect when highlighted after a warm startup (Last crank above 15c/59f)
Enrich (Cold Crank) appears to work when NOT highlighted (Last crank above 15c/59f)

Enrich (Warm Crank) and Enrich (Cold Crank) BOTH highlight after a cold startup (last crank below 15c/59f)
Enrich (Warm Crank) appears to work only when Both warm and cold maps are highlighted.(last crank below 15c/59f)

Warm crank Enrich (Last crank above 15c/59f) AFR becomes ~14.0:1 @ ~10c/50F regardless of ANY settings applied to Temp Enrich, Enrich (Warm Crank) and Enrich (Cold Crank)


On cold mornings (presently around 10c/50f to 20c/68f) I go to start the truck and if it goes to Enrich (Warm Crank) (las crank being yesterday afternoon, HOT) I see maybe 10 seconds tops of rich fuel and then it goes to about 14:1 while warming up.


"Coolant temperature based enrichment offset when last crank < 15degC"
"Coolant temperature based enrichment offset when last crank > 15degC"
Why would warm/cold crank be based on previous start? It seems like it should be based on present conditions since the day warms up and so does the engine the second start of the day should always be warmer than the first.

Is there anyway these could be fixed and combined to read from only the temp enrich table so that regardless of cranking temp it just reads from same table each time?

Nissan wrote the ECU code such that after cranking, it would lock onto a particular table based on the cranking temperature (being above/below 15 deg BDTC)

I have no intention of updating the firmware to customise this further. However I can update the firmware (if I do a feature pack release) such that there is only one table used

What I will do is check the software reports the table usage correctly (by simulating crank during specific temperature on the bench) and check the table follows and fix where required

Issue tracking:
http://www.nistune.com/mantis/view.php?id=23

In the meantime I would suggest making both tables the same values

Matt wrote:Nissan wrote the ECU code such that after cranking, it would lock onto a particular table based on the cranking temperature (being above/below 15 deg BDTC)

I have no intention of updating the firmware to customise this further. However I can update the firmware (if I do a feature pack release) such that there is only one table used

What I will do is check the software reports the table usage correctly (by simulating crank during specific temperature on the bench) and check the table follows and fix where required

Issue tracking:
http://www.nistune.com/mantis/view.php?id=23

In the meantime I would suggest making both tables the same values

Presently I run all 3 tables run the same values "Enrich (Warm Crank)", "Enrich (Cold Crank)" and "Temp Enrich" but it still seems like the enrichment shuts off before the engine is warm enough.

Okay I'll take note when investigating the ECU. Normal shut off about 80 degrees

Ok, I discovered my O2 feedback temp was too low and raised it. Now I can consistently set my warmup enrichment up to about 80c/175f as long as;
1) I keep all 3 maps the same
2) O2 feedback is set to 80c or higher (I will probably be disabling O2 sensing altogether anyway)

Closed this issue out. Feature pack changes this to single enrichment table in F661F firmware