LAMBSE dropping on decel

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EFI66
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LAMBSE dropping on decel

Post by EFI66 » Wed Jul 04, 2018 5:42 am

I think I need some professionel help here, if someone could help me take a look at my J4J1/CBAZA bin and give me a hint on what I am doing wrong.

Having a 1994 5.0 put in a 66 mustang with aluminum heads, GT40 intake, 70mm maf, 65 mm TB and likely an aftermarket cam that I dont know what is. It runs very well when racing.

I believe I got the MAF curve and injectors dialed in and at cruise and normal driving the KAMs are hovering around 0.99 to 1.01 and LAMBSE 14-15

But everytime I roll op to a stopligt the LAMBSES drops untill it ends on the default 10.98. Same goes if I just set it in neutral and roll to the stopligt

I tried adding more Dashpot and changing decay but it doesnt seem to affect anything. It has idle vacuum at 14 and there shouldnt be any leaks. Idles at 850 RPM
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j4j1-mustang66-v14-dashpot.BEB
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skunk
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Re: LAMBSE dropping on decel

Post by skunk » Wed Jul 04, 2018 8:30 am

Lambse at 10.98 means your lean. It's possible you have too much dashpot or bottom of the MAF needs work.

John
1987 Turbocoupe.
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EFI66
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Re: LAMBSE dropping on decel

Post by EFI66 » Thu Jul 05, 2018 8:37 am

I tried adding more flow from 0.7 - 1.0 MAFV without any effect. I already use a GT maf curve with extra 10-15 % and when light cruising the KAM and Lambse seems spot on

Its only on decel that the LAMBSE slowly drops from 14 steadily down to max of 10.98 followed by the idle that starts going up and down untill i accelerate again and the lambse goes back to the 14ish

I am using the J4J1 with 19 lb injectors setting the Slopes equal.. i ponder if this is a slope problem ?

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EDS50
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Re: LAMBSE dropping on decel

Post by EDS50 » Fri Jul 06, 2018 9:58 am

EFI66 wrote:
Thu Jul 05, 2018 8:37 am
I tried adding more flow from 0.7 - 1.0 MAFV without any effect. I already use a GT maf curve with extra 10-15 % and when light cruising the KAM and Lambse seems spot on

Its only on decel that the LAMBSE slowly drops from 14 steadily down to max of 10.98 followed by the idle that starts going up and down untill i accelerate again and the lambse goes back to the 14ish

I am using the J4J1 with 19 lb injectors setting the Slopes equal.. i ponder if this is a slope problem ?
J4J1 is designed for 24# injectors. What are your injector settings set to since you are using 19#s?
1992 LX - 25.1c Chassis, Vortech Blown Dart 332, Lentech Trans, TRZ Backhalf, A9L, Moates QH/SL v1.9, BE, EA, TunerView

EFI66
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Re: LAMBSE dropping on decel

Post by EFI66 » Fri Jul 06, 2018 11:23 am

I set both high and low slopes to 19.64
Min PW: 0.000 msec

and offset:

15.94 - 0.5625
15.00 - 0.5625
14.00 - 0.6875
13.00 - 0.7500
12.00 - 0.8750
11.00 - 1.0313
10.00 - 1.2188
8.00 - 1.8438
6.00 - 3.4688
5.50 - 5.7500
0.00 - 5.7500
0.00 - 5.7500

I can attach a log of the decel from arount the time 274 seconds to 305 seconds (the cars behind hated me)
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4july-decel.csv
(1.13 MiB) Downloaded 4 times

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EDS50
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Re: LAMBSE dropping on decel

Post by EDS50 » Fri Jul 06, 2018 1:18 pm

I would recommend running a T4M0 tune which is set up for 19# injectors. Running your J4J1 with your current injector settings is causing your issues.
1992 LX - 25.1c Chassis, Vortech Blown Dart 332, Lentech Trans, TRZ Backhalf, A9L, Moates QH/SL v1.9, BE, EA, TunerView

EFI66
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Re: LAMBSE dropping on decel

Post by EFI66 » Fri Jul 06, 2018 2:04 pm

Yeah, i know. The J4J1 just pulls much harder and feels like its 50HP extra than the last T4M0 i used

And it runs great - except for the decel problem. I can work around it with OL I guess. Otherwise I need to pull out the T4M0 again and see if I can get it running just as strong as the J4J1 and get rid of the decel issue :)

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EDS50
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Re: LAMBSE dropping on decel

Post by EDS50 » Fri Jul 06, 2018 2:41 pm

The car is running too rich with what you have. Theres nothing you cant do with the t4m0 that you are doing with the j4j1. You can make the same power and correct your decel issue at the same time.
1992 LX - 25.1c Chassis, Vortech Blown Dart 332, Lentech Trans, TRZ Backhalf, A9L, Moates QH/SL v1.9, BE, EA, TunerView

EFI66
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Re: LAMBSE dropping on decel

Post by EFI66 » Tue Jul 10, 2018 2:22 pm

I added 10% to the battery injector offset and tried activating open loop on decel by setting the load to 8 in the FN338

It seems to be able to recover the dropping lambse better.. when it starts plummet from 14-15 towards the annoying 10.98 I noticed it recovered several times in the low 13 -range to go back and stabilize in the 14-15

But after approximately 300 seconds of driving when cruising in lor rpm 1200-1400 along the way with load in the 15 range it suddenly starts plummet again to 10.98 with a hefty surge to follow

Im using BE2010 and logging flag1 and flag4 and I notice that in the ET time of 328 in the attached log there is a flag called ARCHFLG that goes from 1 to 0 to 1 an then the LAMBSE starts crashing

At the same time the ISCDTY goes from 14 to 35 and then swings from 14 to 40

This behaviour goes on until ET 373 where the LAMBSE jumps from 10.98 back to 14.64 where I assume the OL tables takes over and controls it from here.

Can anyone take a quick look at the log and point me in a direction for a fix on this? Would I just need to force it to OL all the time ?

this only happens once the engine is in closed loop and reading the lambses. I have Long Tube headers and know this isnt the best option but its the only exhaust possibility I have on this car.
Attachments
low-lambse.csv
(172.3 KiB) Downloaded 6 times

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