Very rich idle hack

Nistune topics related specifically to the 6303 cpu

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zimzoom_14
 

Posts: 7
Joined: Tue Jan 14, 2020 5:41 pm

Very rich idle hack

Post by zimzoom_14 »

Hi Forum members and Matt
Every 3 or so morning startups my car idles pig rich (7ms injector pulsewidth, where the correct is around 2ms)
The only way to instantly clear this up to nice stable idle at 900rpm at 11ish lamda and 1.98ms injector pulswidth is too open up my 5v 3pin connector to the TPS for about 5 seconds...then reconnect. TPS voltage is 4.6v...warm idle lamda is 13ish.
The car will be perfect for about 3 more days.
I have disabled flag 1in an effort to try sort this as my neutral switch does not work...No change.
I have disabled 02 feedback, and disconnected O2s...no change.
LTFT and STFT amount does not change the situ either.
What is actually happening to the map or ECU warm up idle routine when this 5v is interrupted for a few seconds, and how do i resolve this annoying bug?
Thanks in advance.
Matt
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Re: Very rich idle hack

Post by Matt »

Hi

Need some more details here.

1. What ECU / vehicle
2. Can you post your tune file and log file showing the issue
3. Are you saying the TPS voltage is at 4.6V? It should be sitting around 0.4V normally for most vehicles
4. Not sure what flag 1 is until we know about the ECU (part number needed)
zimzoom_14
 

Posts: 7
Joined: Tue Jan 14, 2020 5:41 pm

Re: Very rich idle hack

Post by zimzoom_14 »

Hi Matt
Here is the current bin that makes the car run well.The car is a 91 TT 2+2 eurospec manual, using a auto ECU (237XO-31POF R:14 U ) as the original suffered water damage.
Here are 2 log files which did not highlight the issue im having, but are good to look at for anything obvious.
One has control flag 1 enabled, the other does not. This flag sees the tps idle switch and the neutral switch when enabled.
Im running dual pop charger filters with single MAF.
550cc injectors.
Bin file is from an auto 2+2 that ive edited to make the car pretty good.
TPS idle voltage is 0.46v
I have had to pull a lot of fuel from the idle area on the fuel map to allow a nice idle.
Attachments
nov 3 flag1 off_2021-11-03_0836_13.csv
(143.21 KiB) Downloaded 50 times
log1_2021-11-03_0839_53.csv
(68.23 KiB) Downloaded 52 times
3 Nov 2021.bin
(32 KiB) Downloaded 58 times
zimzoom_14
 

Posts: 7
Joined: Tue Jan 14, 2020 5:41 pm

Re: Very rich idle hack

Post by zimzoom_14 »

Hi Matt
The start idle fault appeared and is now logged. Look at about 37 sec in where i disconnect the TPS plug for 5secs.
Whilst disconnected, the voltages rises to over 3v, and then corrects to 0.46 on reconnection also stabilizing the idle nicely, as seen by much nicer traces.
The car will now be fine for 5 or so re-starts, but then requires this routine to clear up the very rich idle/run condition.
Any ideas to sort this funny situ out is very appreciated....cheers
Attachments
tesst log idle bad nov_2021-11-04_0832_16.csv
(259.15 KiB) Downloaded 55 times
RomChip200
 

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Location: FRANCE

Re: Very rich idle hack

Post by RomChip200 »

You have low latency, 620us.
Raise the latency value e.g. 900-1000us and you can smooth out the fuel map for low TP.

What is your fuel vs. max. boost ? You have big timing advance.
Matt
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Joined: Sun Jan 29, 2006 1:45 am
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Re: Very rich idle hack

Post by Matt »

Must have missed the update for this one. What I can see is the VCT flickering on off all the time

This is due to the adjustment of K constant from 288 to 550 (why was this done?). I would expect 370CC to 550CC injectors to just adjust the TIM parameter. Not K also

Anyway adjustment of K increases TP about double so it affects load referencing in the map, knock, closed loop, VCT etc

Put K to factory, adjust just the TIM and that will put load references back to normal

Compare against the 31P0F factory tune and look over other parameters. High gear coef parameters dont make sense, and there are various other things modified in there which probably dont' need to be
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