Crome, jerky at low rpm

[dwhacks]

I've googled all I can and tried a few things, but I dont have much (any) knowledge. I have a Delta 272 regrind, 68mm TB and intake manifold with IAB's from an H23 on my f22a. I have a chipped P06 ecu with IAB control kit, modified for 5v wideband and I'm using free Crome and Freelog.

I've got my tune getting pretty close, and I'm narrowing down the issues. I think I still have a heatsoak issue which I haven't attempted to solve yet, but my big problem is the jerky low RPM stuff. When driving really slow in 1st gear it can be jerky, or when coming to a stop before depressing the clutch it can be jerky and worst of all, sometimes when accelerating when shifting from 1st to 2nd it can be violently jerky.

I have read this from another site:

in the top bar plugins>control>advanced idle

initially it was set to between 1800 and 750 and one was up to ~8500

i set all of them to 1300 and 750.

and set the IACV slider to -10

This seems to help some, but has also made my cold idle a lot worse.

Anyone able to help me on this one? I would pay to have someone tune my car but I live in the middle of no where and would still like to learn how to do it.

[cb9love]

with the slider in the negative you are making your car have negative idle air control.
after the car warms up i set my base mechanical idle. I slide the slider over until the car was idling correctly. It will rev up at first then drop to it's new idle. I only needed +18 to get the iac right. Those other adjustments also have to do with idle at different starting temps.
I am not sure why you are jerky but what you are adjusting is idle not moving.
Open up and look at the map a dozen more times and you may start to understand it eventually.

[dwhacks]

Well I would have agreed with you before, but googling the situation suggests otherwise. It seems as though at certain RPM and vacuum levels, under certain conditions, the ecu cuts the fuel as if its trying to idle.

[cb9love]

right but that is under a different setting in the advanced settings. That would be under idle while moving
EDIT; my bad your in a different portion of crome than i was thinking
I didn't find any need to adjust those settings.
I still stand by your cold idle is worse because you have your iacv working negatively.
I try not to adjust the settings on my map until i understand what they are changing.
if you want to make wild changes on your map make sure you save a copy of your last best working map.

[93redcb7]

post a picture of your timing map and fuel map

[dwhacks]

heres a screenshot:

[djcaz_aom]

Ok, now I am confused.

Is this a turbo car? If not, why do you have so many columns? They are not necessary in an NA tune.

I too agree your iac setting is too low.

I would start on a fresh map and copy over leaving the advance settings alone.

[dwhacks]

I know, I got the basemap from someone with a similar setup and they had added the turbo columns. I don't know how to remove them, and I was worried that if I start from a fresh map then some of the other adjustments I don't know about will not transfer over. Its not like those settings will affect anything anyway as the vacuum will never reach those regions.

Also, I have worked on my idle a bit last night, and put the IACV slider at around -3, where I've found it to idle best, around 14 AFR. Cold start will idle a bit rougher and quite a bit rich around 12 AFR, but it did seem to raise the idle as it should to heat up.

Playing with the "advanced idle" settings has greatly improved my low speed driving. I can actually go on flat ground in 1st gear with no throttle and it doesn't jerk. I still did get a little jerkyness a few times after shifting to 2nd, and when the car is cold it is jerky.

[dj_ender]

I had this very issue and it was do to my TPS not being calibrated correctly.

[dwhacks]

I had this very issue and it was do to my TPS not being calibrated correctly.

Good call, I have been screwing around since setting my TPS, I will have to try the "calibrate tps" option. Thanks for pointing that out.

[dwhacks]

Well its not the TPS. Freelog says my TPS goes from 0% to 101%. I can't imagine anything being wrong with that.

[dwhacks]

right but that is under a different setting in the advanced settings. That would be under idle while moving
EDIT; my bad your in a different portion of crome than i was thinking
I didn't find any need to adjust those settings.
I still stand by your cold idle is worse because you have your iacv working negatively.
I try not to adjust the settings on my map until i understand what they are changing.
if you want to make wild changes on your map make sure you save a copy of your last best working map.

BTW, here on page 11 is where it talks about the advanced idle. It seems to say I am using it correctly.

[NTYPE]

your ignition map looks a bit rough around the low rpm low load area. see at 1000rpm you're pulling 17* timing and then at 1500 rpm it jumps up to near the 30's you might want to insert an extra row at 1250 to help smooth it out.

The fuel map kinda does the same, it looks like the idle areas have been adjusted a lot but the light throttle hasnt been transitioned to suit, check out your 2D graph for the ign and fuel maps, if the lines are all jagged and rough then thats how your engine is going to run aswell.

[dwhacks]

So I should change my scalars? I can't add an extra row can I? I dont know how if there is a way.