short term fuel trims and idle

[slowpoke2006]

I'm trying to get as much done as i can on a street tune before i go to a dyno and finish it out @200 an hour i dont want to be there any longer than i have to be. I just have a question about the short term fuel trims mine are running about -10 to -5 and long term are all right at -1, but I'm idling around 15.1 afr and some times higher that's at temo idle. I think that may be cause by my BOV leaking. but would it be better to adjust the k constant or Injector Latency to get my fuel trims closer to neutral. Just trying to keep from leaning idle out while trying to adjust stft. Not sure if it matters but im using a 95 300zx O2.
Thanks
James

[Matt]

At what point is it -10 to -5? Some of these ECUs do not report correct trim until at cruise. So ignore it at idle if that is where you are seeing it

If lean at idle only then increase latency further to improve this (or increase TP min table if lower than factory values)

[Torque]

From my experience the Z32 ECU does not adjust for lambda until you put it out of neutral.
(press clutch, put in a gear)

Check your logs for that behaviour,there is no fluctuation of the O2 voltage until out of neutral.

[slowpoke2006]

Its at cruise that i see it at -10 to -5 I'm thinking i can just adjust my fuel map table to fix that correct? Im using an rb20 ecu for the rb25det. I dont see my o2s being read at idle it doesn't start using the O2 until my tps idle trigger voltage is reached. I'm fairly sure that it never uses the o2 for idle.i can hold it at 2500rpm and my o2 will bounce lean rich from 14.2-14.9. My neutral light in nistune never comes on. Not sure if its connected to the trans or not..

[Torque]

You will need to adjust K, not the fuel table.

The Alpha Learn (or fuel correction factor ) is basically the difference between the injected fuel to achieve lambda 1 (based on ECU calculations/injector capacity ) and the actual lambda reported by the O2 sensor.

It seems your K value might be a bit too large, telling the ECU the injectors flow less than they actually do, that's why the fuel correction is slightly negative.

I never got my fuel correction to zero it's between -4 and +5, depending on driving.

[Torque]

To actually log trims and adjustments you have to rev the engine above idle.
Only putting it into gear (out of neutral) is not enough.
(I remembered this wrongly)

[slowpoke2006]

Ok thanks I will do some more logging and adjust k some once i get the car back running. My Starter decided it was going to go out today. Yay me. I know its going to be a pain in the but to get to and get change, and the fact that i cant just walk into a parts store and get a new starter for it.

[Matt]

My neutral light in nistune never comes on

Sounds like it may not be. Also check 'Digital control register 1' is enabled when connecting to consult. This register reads TPS idle, start switch, air cond, neutral etc

[slowpoke2006]

Yea its checked the TPS idle shows up when im it at idle.Im not sure if mine is messed up or what. its got 3 connectors on it, i know one is speedo, and one is for back up lights for reverse. not sure what the 3rd one is for and i haven't pulled a FSM to see what it is yet. will do that later. The starter was a lot easyer to remove than i thought it was. I think that a starter from an old 68 datsun sportster will fit and work for $68 ill give it a shot. from all my searching on line people say it will and looking at it on line the body and solenoid is larger but everything is in the same places.