I read through this thread and think my problem is similar
https://my350z.com/forum/tuning/498123-haltech-burbles-and-pops-on-decel-transition-3.html

it is giving the tuner fits. When the car was previously tuned it was there and I have always just dealt with it.
setup
greddy twins
Dw 800
haltech harness
Bc stg 2 cams
built motor
south Bend clutch
I think jwt flywheel it has been a while
maf deleted
external map sensor
gm iat

what it does:
so on the street and dyno if you're just driving and maintaining speed similar to cruise control the car will just jerk or buck once. It skips a beat but if you give it some gas all is well which makes me think it is similar to cruise control and decel cut.

coil packs have all been swapped and plugs checked.
tuner has been on the dyno for days trying to figure it out. This is his first round with haltech.

I think it is a haltech settings issue with it still talking to the oem ecu. I wanted to go full standalone and this is why. get rid of the 2nd ecu bs and eliminate the source of problems.

car will rev to red line without issue. car was run. on 5 and 8 psi on previous tune without issue to red line but still had the buck.


thinking it could be
app and Tps volt settings
Dw injector latency settings
threshold values for min inj Pw before cut

your thoughts?

 

bump

previous tuner set the threshold to .75 but the ignition retard is 5 degree...is that too much? others only use 0 and base map is 2. Would 5 degree cause a slight buck?

 

WHat do the logs show during the bucking? You should be able to tell very easily if it's going into decel cut by watching the IPW.

Make sure the minimum injector time isn't too low. Could be going into essentially a fuel cut if the IPW drops too low.

 

Wow I didn't know it was their first hatch tune. That's kinda surprising to me. GL Cux hope its resolved soon

 

Sorry DJ didnt know you had replied.

Appears to be the transient throttle table. It is only supposed to be adding fuel but it seems to always be adding which is causing the ignition time to studder.

It was set to go up to 4k rpm. After 4k rpm the car was smooth as butter for free revs and holding rpm. Set the transient throttle fuel to all 0 and the whole rev range was great.

Looking back at it, the tuner loaded a base map setting there where my previous tuner had set up that portion of the table with much smaller values. Car has always had a small chug when trying to steady cruise under load.

So now that we know the cause we can work towards a solution. The base values were up in the 6ms range and 300 cc injectors...I have 800cc injectors and the previous tune had values in the 1/4ms range.

Now to keep making progress...

I wonder if the haltech was adjusting the ignition instead of fuel since no other ignition adjustments were being made. It does have some glitches so its not out of the question.

The transient table starts at 10 with no 0 line...would that mean at ranges below 10 it would extrapolate? 10 being the delta load of TPS ect. Very small table.

 

reading this via a google search, so late reply. But you have throttle jitter. Set the delta load dead band to 0.2% and then reinstate your transient fueling. Try some rapid pushes of the throttle while logging and see if it has the appropriate effect. With no transient fueling, I suspect it will feel hesitant because of lean tip in.