OL Tuning Idle Misfire - Tuning Forum

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OL Tuning Idle Misfire
Wednesday, June 29, 2011 10:53 AM
I try to tuned my IPW table in Open Loop (% afr error) and everytime i approach to 14.7 afr idle, i have lot of misfire on cyl 3 (PID misfire cyl3 on my log table). The Misfire drop my afr to 18.0 and oscillates to14.7 and drop 18... but idle @ 13.5 afr, for exemple, i have never misfire.
I have change all my spark plugs and it's the same think again. The misfire are intermittent, some Start misfire idle and other start later no misfire idle at the same afr. Sometime in CL idle @14.7 afr it's the same think (Misfire cyl3 PID on my log table).

Also, I have problem starting when engine is hot, I have to press the thottle to start.

I need your advice and experience with my problem.

Thank



Boost Lover

Re: OL Tuning Idle Misfire
Wednesday, June 29, 2011 12:19 PM
Need more info..... Mods/Copy of file and log...



P&P Tuning
420.5whp / 359.8wtq

Re: OL Tuning Idle Misfire
Wednesday, June 29, 2011 4:55 PM
J-body L61Turbo, 60 lb/hr injectors, Map sensor 1 Bar, NGK LTR7-IX 0,035" gap.
My WOT VE are not tuned for yet. I just have tuned IPW table (%afr error) with the stock VE on idle and Low Throttle.
Open Loop.hpt disable DFCO. Custom PID WB with A/C Press

.hpt file : http://www.4shared.com/file/a2hu19Dt/IPW_Open_Loop_Tuning.html

Misfire cyl3 log .hpl with my Open Loop.hpt : http://www.4shared.com/file/NSDutc-A/IPW_OL_Tuning_Misfire.html

I need your advice and experience with my problem.

Thank



Boost Lover
Re: OL Tuning Idle Misfire
Friday, July 01, 2011 12:06 AM
You may also want to post up your config file too.





Save your money. It might be worth something someday.

Re: OL Tuning Idle Misfire
Friday, July 01, 2011 2:03 AM
I like to tune idle and cruise with the fuel trims personally. I find it quicker, easier, and more accurate. Just have to make the custom pid of LTFT + STFT. Might fix your issue too.


1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by: Kronos Performance

WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer
Re: OL Tuning Idle Misfire
Sunday, July 03, 2011 4:37 AM
If you have any suspicion of hardware issues, it's important to fix those first before trying to tune around them.



Re: OL Tuning Idle Misfire
Sunday, July 03, 2011 4:41 AM
oldskool wrote:If you have any suspicion of hardware issues, it's important to fix those first before trying to tune around them.


yes this. Finally got my aem fpr in. car runs so much better and the tune looks a lot more sane now.


1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by: Kronos Performance

WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer
Re: OL Tuning Idle Misfire
Sunday, July 03, 2011 5:00 AM
oldskool wrote:If you have any suspicion of hardware issues, it's important to fix those first before trying to tune around them.


Truer words have never been said.



FU Tuning



Re: OL Tuning Idle Misfire
Sunday, July 03, 2011 8:52 AM
Screaming for Mercy!! wrote:
oldskool wrote:If you have any suspicion of hardware issues, it's important to fix those first before trying to tune around them.


Truer words have never been said.
Could not agreet more. To the OP, I won't look at the files on a Share site... Too much risk for Viruses.. you can email them to me and I will take a look...



P&P Tuning
420.5whp / 359.8wtq

Re: OL Tuning Idle Misfire
Sunday, July 03, 2011 10:34 AM
QWK LN2 (P&P Tuning) wrote: Could not agreet more. To the OP, I won't look at the files on a Share site... Too much risk for Viruses.. you can email them to me and I will take a look...


Email sent !!!

I do some test with other tuned (Old tuned with fake injector constant 0,095 make by bad tuner) and he don't have misfire idle and less dificulty to start engine when is hot without to press throttle @ 100%.

If i have to press throttle to start engine when is hot, is because the tuned are too lean or too rich on idle table ?


Boost Lover
Re: OL Tuning Idle Misfire
Monday, July 04, 2011 9:26 AM
Replied to your email..... I see some things, but will comment after you reply to the email....





P&P Tuning
420.5whp / 359.8wtq


Re: OL Tuning Idle Misfire
Monday, July 04, 2011 12:57 PM
Ok.. Got your response.. First off, put your IPW modifiers all to 1. The settings you have are all over the place. Also, fix your commanded PE... You are commanding 14.7 with a modifier of 4.XX :1 . I also noticed that all the misfies appear to be on #3 cyl. I would do a compression test and make sure the cylnder is good..





P&P Tuning
420.5whp / 359.8wtq

Re: OL Tuning Idle Misfire
Monday, July 04, 2011 1:02 PM
You don't need your ipwm table to be all one. But we'll save this discussion for another thread. maybe later I'll make at thread taking about the two different styles and their characteristics.


1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by: Kronos Performance

WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer
Re: OL Tuning Idle Misfire
Monday, July 04, 2011 1:04 PM
I believe he was trying to use my method of dialing in injectors via the IPW vs VAC table. I guess i was not specific enough to tell him to keep it very smooth...



Re: OL Tuning Idle Misfire
Monday, July 04, 2011 1:07 PM
Or he left it stock, which is a bit all over the place. Can't be as bad as mine was just before I switched regulators. Lets say I had a 0.6 on there and a 1.4. It was not pretty.


1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by: Kronos Performance

WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer
Re: OL Tuning Idle Misfire
Monday, July 04, 2011 1:12 PM
Leafy (Club Jeffie FEA man) wrote:Or he left it stock, which is a bit all over the place. Can't be as bad as mine was just before I switched regulators. Lets say I had a 0.6 on there and a 1.4. It was not pretty.
His is all over the place....


Injector Pulsewidth Multiplier vs. VAC

1.00000 1.00000 1.00000 1.13080 1.29291 1.33267 1.24878 1.23349 0.98291 1.04019 0.96075 0.95306 0.93317 0.95053 0.92853 0.94083 0.93207 0.94159 0.92642 1.00000





P&P Tuning
420.5whp / 359.8wtq

Re: OL Tuning Idle Misfire
Monday, July 04, 2011 1:19 PM
Yea sounds like a hardware issue. But in any case the table should be smooth if using it to tune injectors Def not up and down.



Re: OL Tuning Idle Misfire
Monday, July 04, 2011 1:38 PM
Compression Test :
#1 185 psi
#2 190 psi
#3 195 psi
#4 190 psi

Why change Commander PE ? If i want 12.0-12.2 afr WOT i enter 12.0 in Commander PE all table and 1.0 all over the place in multip x rpm PE, if i understand ?
But in cruise condition and Idle i want 14.7AFR. I thought he was 14.7 on Commander PE and mutipl PE for the AFR WOT.



Boost Lover
Re: OL Tuning Idle Misfire
Monday, July 04, 2011 1:42 PM
PE is Power Enrichment (commaned target value only).... Yours says 14.7 across the board, and your RPM modifier commands a 4:xx ....With these values being incorrect, it will cause your scanner/histograms to give you the incorrect error % value....






P&P Tuning
420.5whp / 359.8wtq

Re: OL Tuning Idle Misfire
Monday, July 04, 2011 1:48 PM
Yoecotec wrote:Compression Test :
#1 185 psi
#2 190 psi
#3 195 psi
#4 190 psi

Why change Commander PE ? If i want 12.0-12.2 afr WOT i enter 12.0 in Commander PE all table and 1.0 all over the place in multip x rpm PE, if i understand ?
But in cruise condition and Idle i want 14.7AFR. I thought he was 14.7 on Commander PE and mutipl PE for the AFR WOT.


We can only adjust afr in pe mode. make that multiplier table all 1 and set the pe afr table to what you want the pe afr to be.


1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by: Kronos Performance

WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer
Re: OL Tuning Idle Misfire
Monday, July 04, 2011 2:05 PM
Thank everyone
I will try this !


Boost Lover

Re: OL Tuning Idle Misfire
Monday, July 11, 2011 11:46 AM
I think i have found my problem. I have install a Gauge press in my fuel line. My press is 32psi all time, idle and low throttle. I check with the manufactuer Spec's and it's supposed to be at 50-60 psi Idle. I think i have blocked Fuel Filter or problem with my stock fuel press regulator


Boost Lover
Re: OL Tuning Idle Misfire
Monday, July 11, 2011 11:54 AM
At least yours made sense mine is all over the place. I'm going to guess weak spring in the regulator though, because the clogged fuel filter would give you lower pressure the more fuel you asked of it (ie the higher the rpms/boost the lower the fuel pressure), same with a bad pump.


1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by: Kronos Performance

WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer
Re: OL Tuning Idle Misfire
Monday, July 11, 2011 4:39 PM
WOT the press drop to approx. 22psi all long but i think it's normal 10 psi of drop between Idle&low throttle to WOT. I will do test with other Stock FPR to see if is was really my problem.


Boost Lover
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