Nistune Forums

Hi,

I feel bad that my first post is asking for help and im sure you get tired of noobs like me asking questions, but I was wondering if anyone could have a look over my tune and log file.

Info:
S14a w/feature pack
nismo 740's
Z32 AFM
Have confirmed timing and TPS are set correctly
SR20VE throttle body (I dont think this should mess with anything)

I paid a workshop to do the tune, but there's still a lot of things I need to work through before playing with the feature pack goodies. There are 2 problems I would like help with, the first being the idle dropping too low when idle conditions are met. Before I adjusted the injector latency it would stall or drop down to 250 and recover, now its mostly fine, occasionally drops down to ~500 before recovering. I cant seem to get it any better from playing around with all of the idle controls, wideband Lambda is ~1.00 on idle.

The 2nd problem is when rolling off the throttle and holding it at about 5% open the car will sometimes surge like I'm bunny hopping the car opening and closing the throttle. At first I thought it was a reversion issue but sometimes it will do it when under low load. The log file captured this happening.

Lastly when I was looking through the tune I noticed the TP K Const is about double the factory value at ~60000, from what I've read its best to try keep this as close to the factory value as possible?. To keep it as close as possible would you use the VQ quantifier and total injection multiplier?. Any comments on the tune are appreciated and thanks in advance!

Matt.


Edit: Just realised I should be doing the logs in stream mode, will attach a new log tomorrow arvo

Its more that it is best to keep TP in the same range as before and leave the TP scales as factory when your board has Feature Pack loaded on it (which it does)

TP (load) = MAF/RPM * K Constant

K constant can be adjusted where the load on the vehicle has changed from factory (and this happens once you change to the Z32 MAF)

Basically you are correct here in that the vehicle has been tuned using the usual methods (resizing K constant and the TP scales).

At this point I would
1. Put the TP scales to factory values

2. Then look at pulling K constant back until the vehicle operates within those scales (offset any fueling adjustments using Total Injection multiplier (TIM) to get AFRs back to where they were)

3. Reenable Feedback Switch 1: O2 sensor and then make sure your O2 STFT and LFTFT trims are close to 0% at cruise to know you have fuel trims (adjusted with TIM) in the right place

4. Increase TPmin load higher to add more fueling if you are getting lean around idle and increasing latency is not enough to fix the issue

Check the AFRs and listen for knock over the tune since scales have moved around a little

Thanks heaps. I was sitting there today at work thinking about it and then suddenly everything made sense. 02 is turned off because sensor is broken. Is the launch control switch feature working properly for this ECU? my switch isnt doing anything, yet to double check wiring.

Better log attached. You can see where I roll off the throttle, hold it for a while and then let off completely. There is alot of spiking going on, reversion is happening but not sure if its the cause. Im not too concerned with this now until i fix the TP scales and put in a new sensor.

Thanks for your help

Yes launch works fine. I have an S14A myself so was the main ECU I worked with. Check your engine light when launch is enabled to see it is flashing (tickbox to make it flash)

The launch control is works perfectly except for the switch.

I have mine wired to a brake light switch on the clutch pedal. The engine light will flash and Power Steering SW goes active in the gauge readout when I push on the clutch pedal but as soon as I rev over 1100ish the launch control is disabled, seems to be pretty consistent with Idle SW being de-activated. The Power Steering SW stays active the whole time I've got the clutch depressed.

That is your problem then... Your power steering switch operation should be momentary and not held on. The wiring is causing this issue. It should only be pushed on for half second

Same as this problem here:
http://www.nistune.com/mantis/view.php?id=62

Ah ok, sorry, it was recommended i use that kind of switch but I should have looked harder on here when it wasnt working!.

Everything else is working perfectly now after doing what you recommended, car drives as smooth as from the factory, thanks for the help

Excellent!