issues with tune

Fordy · Post by **Fordy** » Sat Jan 16, 2010 5:23 am

having a few problems which i hope someone can help me out with

1. random spikes or dips of injection ms in log
2. random spikes or drop outs of rpm signal in log but unable to see it on rev counter
3. unable to map out lean spot as i come onto boost

few specs
sr20det
nismo 555's
standard afm
t28 turbo hybird with 360 thrust bearing
forged pistons
1.2mm metal headgasket
recently new ngk 7 irdiums standard gap

ive attached the bin and current log to suit it

ony thing ive changed since that log was the ttpmax at 2400rpm as it was set to 76 not 255 but i cant find the log stored anywhere even when i click yes to store it.
Its got better but its still not right as it goes rich then lean then rich on boost just after the transition its driving me nuts now

PL · Post by PL » Sat Jan 16, 2010 10:17 am

Which model SR20 is it?

PL

Fordy · Post by **Fordy** » Sat Jan 16, 2010 11:26 am

200sx s14a

PL · Post by PL » Sat Jan 16, 2010 12:41 pm

Hmmm. I see the dropouts but I'm at a loss to explain them. Usually if the AFM voltage changes then so does the injection time. My guess would be electrical noise causing the dropouts. I see RPM dropping to zero at one point - that's gotta be bad data!

Note that if you go into "Streaming" mode instead of "Tuner" mode you'll get a lot better resolution in the logs. Might help a bit.

I loaded up 83F00 to compare and I see some of the enrichment tables are different to std. Might be something to check there. Or I might just have the wrong bin. I see a lot of the log was done while the engine was warming up. So those enrichment tables would be affecting things.

So you've definitely got the right AFM on it? I've seen a couple engines where people selected the wrong VQ map for the AFM they were using and it caused problems like you describe.

Sorry, that's about all I can think of at this stage...

PL

Fordy · Post by **Fordy** » Sat Jan 16, 2010 9:09 pm

im assuming the right afm is on the car but the car has had a few previous owners so i cant be 100%, just went throught looking at different afm maps and all of them go lower than the one i have so i'd thought if i changed it to anything else it'd make it leaner rather than richer?

i'm going to check all my connections in the engine bay like the cas connector and clean every single earth point. might even disconnect the apexi safc2 from the ecu wiring aswell

i've changed a few things in the map and will go out and get some logs
1. ttpmax now 255 starting at 1200rpm not 2800rpm
2. increase fuel map copied from file in rom pack
3. o2 feedback switch back on (o2 sensor disconnected currently)

im hoping its just the ttpmax thats wrong again but im not holding my breath

Fordy · Post by **Fordy** » Sat Jan 16, 2010 10:46 pm

just been out and its still the same

altho i've worked out its only doing it when i got from cruising throttle to instant full throttle?

if i slow depress the throttle pedal it will drive fine with rich mixtures

im thinking it could possibly be the maf sensor faulty? the one fitted is the correct one

i've attached my latest map and log in stream mode

Fordy · Post by **Fordy** » Sun Jan 17, 2010 5:34 am

update

went around all the connections in the engine bay and tighten the pins up...
seems to of made the engine run smoother and its slighty richer off boost

but its still the same coming on boost going lean....

So i started again...running adjustable actuator boost set to steady 0.7
Filled the tank full of fuel
Zero'd the fuel map
Zero'd ttpmin and maxed ttpmax
Tweaked k constant from 22071 to 18905 with latency of 710us and got cruise to 14.7ish
Idle went rich to 13's so raised ttpmin from 0 to 2 to get the idle around 14.7
The car is driving really nice like that off boost
Then i changed the map from 24 onwards to 11afr (+43 in the map cells)

and it still goes lean up to 16afr's when planting the throttle

so after a hour of no improvements i came back in

ive been told i could be the accel increase fueling? but when i adjust it, it doesnt make any difference?

Fordy · Post by **Fordy** » Mon Jan 18, 2010 10:42 am

let my friend do the mapping today

list in order of things done
k constant reset to around 23000 ish
latency set to 710us
adjusted maf translation map to give the correct target afr's in fuel map when demanded but bit richer than targeted at high revs+ high load which is fine, but map translation map adjustment has fixed the going lean problem
also timing map roughly mapped safe atm till det cans are put on it