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LSJ Tuning Woes
baustin
Well-Known Member
- baustin Well-Known Member
Also about the misfires, since cylinders 1 & 4 have the misfires almost entirely, I'd assume if there were injector issues, it's just those 2. Swapping the plugs & coils over from 1/4 to 2/3 would be good to know if the misfires travel with the parts or stay. Swapping injector position is a little more involved but would be helpful if the misfires stay at 1 & 4 after the coils/plugs are moved.
My original misfire issues were across all the cylinders.
My original misfire issues were across all the cylinders.
- Gtstorey Goblin Guru
I agree with most or maybe all of what baustin has said. The only spot I might deviate is that maybe the misfire problem is possibly coming from the tune. The misfires are being proceeded by a large difference in the air flow as shown by the maf & dynamic airflow (which are similiar) and the VE airflow, and it looks like it's while decelerating from this limited sample. The maf, DA and VE should be pretty close. I'm not sure why it would only cause misfires on 2 cylinders but maybe those cylinders have problems and are not firing correctly when they start going lean/rich. I would still probably move the components around to see if the misfire follows.
You are getting AP readings of at least 150%+ so maybe leave that system alone. (assuming you made pedal stab at 5:46)
The more I look at this the more I think someone started tuning it that didn't finish, hence why your dynamic air flow is disabled. I would compare injector part #s with baustin, and if they are the same, copy his settings into your tune and then go through the basic tuning steps for the LSJ. If the injectors are not the same, I think I compared your data to the injector data on zzp site when I looked at your tune before and it matched, but you need to confirm it is the same injector.
You are getting AP readings of at least 150%+ so maybe leave that system alone. (assuming you made pedal stab at 5:46)
The more I look at this the more I think someone started tuning it that didn't finish, hence why your dynamic air flow is disabled. I would compare injector part #s with baustin, and if they are the same, copy his settings into your tune and then go through the basic tuning steps for the LSJ. If the injectors are not the same, I think I compared your data to the injector data on zzp site when I looked at your tune before and it matched, but you need to confirm it is the same injector.
Ghostknife
Goblin Guru
- Ghostknife Goblin Guru
I have the Siemens DEKA 107961, 60lb injectors. Ill check the map sensor when I get home. I will also swap coils and plugs when I get home and take for a ride.
Ghostknife
Goblin Guru
- Ghostknife Goblin Guru
I will check that when I move them over to make sure they aren't off, What is everyone running for gap? I am seeing a recommended .040 for a 2.8" pulley
Robinjo
Goblin Guru
- Robinjo Goblin Guru
The SS forum is saying 0.032" or 0.035" but that is on the 1-step colder plugs, they are saying everything gets that gap? I'm curious as well, I plan to go with the NGK 1 Step Colder Plugs SKU: BKR7E after the engine runs.
You could call OTTP or ZZP and see what they recommend?
You could call OTTP or ZZP and see what they recommend?
- Gtstorey Goblin Guru
I think you are worrying a little to much about the gap. If buying new plugs, maybe go 1 step colder, but I stock gap should be pretty good, or maybe a little tighter. I don’t think the boost will be anywhere close to blowing out the spark. Mostly make sure the gap on 1/4 is not different than 2/3.
Robinjo
Goblin Guru
- Robinjo Goblin Guru
Checking to make sure the gap wasn't different at the suspect cylinders vs good cylinders was my main intent, but it turned into a gap discussion as well. Might as well set it while checking it out, right? Most likely it's not the gap, but just throwing out other ideas that could be an issue or one of many issues. Sometimes it's simple things that cause issues all while we think it should be much more complex. I like checking easy and free things first, just as a standard operating method.
Ghostknife
Goblin Guru
- Ghostknife Goblin Guru
ill check it while out, the Plugs that came out were NGK BR6EIX, which I believe is 2 steps colder. I will verify but I believe that I put in NGK BR7EIX plugs
baustin
Well-Known Member
- baustin Well-Known Member
It looks like the spec on your injectors match what I got through ZZP more recently based on the spec's shown 107961 vs sourced recently from ZZP. I don't have the model # written down from when I installed mine, I'll see if I can read it from an injector this evening.
The spark plugs I'm running are NGK 4644 Spark Plugs (.035 gap).
The spark plugs I'm running are NGK 4644 Spark Plugs (.035 gap).
Ghostknife
Goblin Guru
- Ghostknife Goblin Guru
ok, new plugs gapped at .035, the old plugs were gapped at .028. I also swapped coils from 1 and 4 to 2 and 3. same tune
Ghostknife
Goblin Guru
- Ghostknife Goblin Guru
after i got home, i changed to the tune that was sent by baustin and re-ran
- Gtstorey Goblin Guru
This last log looks like it happier. Misfire counts are way down. Are these logs the same drive? They are about the same length and similar pattern of RPM. You still have a couple of times that your 1/4 cylinder misfires start to climb and once enough to kick it into OL-fault. The MAF and VE air are still wildly different during these times.
I think you need to take a shot at tuning your maf and VE tables for your particular set up and see if that helps.
I think you need to take a shot at tuning your maf and VE tables for your particular set up and see if that helps.
Ghostknife
Goblin Guru
- Ghostknife Goblin Guru
It seemed smoother for sure, I’m still in a form of limp mode, not boosting more than 4-5psi. They were not the same drive, I did a hot lap, came home and loaded the different tune and did another
baustin
Well-Known Member
- baustin Well-Known Member
It looks like there are at least some tables that you didn't copy over, I see your first gear BCS still was targeting 75% whereas my tune has that at 85%. If only some tables were updated, it could be causing odd behaviors.
This is a screenshot of your data log:
Here's a similar screenshot from a recent data log I did:
I don't know what your foot was doing but it looks like there is a lot of bouncing in the throttle trace which comes from the accelerator position being all over the place. Your injector DC % and INJ B1 (ms) values are far lower than mine at that similar time and this is during open loop with AFR target of 11.3, yet your open loop fuel tables were essentially identical to mine. That must mean your air tables are off if it thought it only needed a small amount of fuel to hit 11.3.
Not sure if you provided this detail and I probably forgot to list it, what octane fuel are you using? My tune is for 93.
Other basic questions you may have covered but are worth asking:
are you sure you don't have any intake path leaks?
do you have all of the intake paths connected or plugged?
have you tested your boost control solenoid to see if it functions (this bypass valve with 2 hoses that rot away, youtube link to test it)? if it's actually opening all the time then you'll have a massive boost leak and limited to low boost and I would expect misfires from wrong air calcs
Ghostknife
Goblin Guru
- Ghostknife Goblin Guru
I’ll take a look at the tunes for comparing tomorrow at work and I will re upload. The video you linked may be onto something, he mentions a rattle coming from the boost bypass. I’m gunna have to check that because when it was idling I thought I heard noise coming from it. It’s on the trailer so I will tinker with it at work tomorrow. All I have run through it is 93 for fuel. I will check tomorrow for vac leaks as well.
