Sudden dip in ignition advance

[samd1985]

I have recently had a K-Pro fitted to my Honda civic type R and mapped to my mods (all bolt-ons and i'm N/A). KManager version 1.4.0.0 feb 2010

i have a few niggles at the moment and having tried everything i can find on here to resolve them i've now run out of ideas. My tuner is also looking into this and is a bit baffled, although suggests the issue may lie with my TPS.

Anyway, here are the symptoms:

MAIN PROBLEM (see attachment): Ignition advance drops off suddenly for no reason when trying to hold a steady rpm in any gear (more noticeable in lower gears as a sudden and short loss of power)

I get a slight 'kick' as if i've touched the throttle slightly when coasting along on the motorway for example at 0% throttle, i.e. decelerating under braking.

my idle when cold or cool will sit around 1500-1800rpm quite steadily, but then lift a few hundred rpm for a second or two, then return back to normal and will repeat this a few times before the engine is warm. sometimes this is present very slightly when the engine is up to temperature, but not always.


Things i have tried so far:

Cleaned and oiled the IAC valve - very smooth now but it spun freely prior to cleaning

set the TPS to -0.9 at 0% throttle and 100 at WOT, as per the 'read' button and the stickied thread i read on here about surging idle

ticked the box for tip-in bug fix

Moved the slider across to catch the rpm as they drop from 3000 back to idle - this is ok

re-visited my tuner (a very experienced Hondata tuner with a superb reputation) who checked the parameters etc, tested a few changes but still no joy.


Can anyone help with this? it's annoying as i'm struggling to enjoy the newly tuned car as much as i could.

Thanks in advance,

Sam

[Piv]

Hi Sam, can I ask where did you get your car mapped ?

We are in Surrey and I can check if you want for you, we have this problem before and it appears that the TPS was faulty, not completly faulty but enough to cut the ignition for a quick moment, you can try if you want

[Hondata]

We've seen this with a bad TPS too. Graph your TPS and expand the scale so that the min is 0% and max 25% - you may see some noise on the signal.

The other thing to look at is the Honda tip in retard bug. This is a bug in the ECU code from Honda which seems to be worse if the TPS is slightly noisy. Try fixing the bug (under 'Gear Compensation') to see if it helps.

[samd1985]

thanks for the replies. i shall try graphing the TPS later on - just explain if you could exactly how i do this?

i have now managed to fix the dipping ignition advance by setting the TPS ignition retard to -100% in each gear under the 'gear comp' parameters window. I still get the 'kick' on deceleration under engine braking and also a random lifting idle on cold start as before, so i will be changing the TPS tonight hopefully a i think i've sourced a second hand one. Hopefully this should be the ed of the problems

Sam