LS3 E38 swap MIL flickering but no DTC?s and very low misfire detection

[TRStech]

Hi,

my LS3 swaped Toyota 86 is driving me crazy. Setup:

-LS3 6.2L out of Camaro SS ?13
-Shorty headers
-HJS E5 converters
-headers and converters fully heat isolated with 5mm ceramic mate + stanless steel manteling
-custom coil relocation + scott performance wires to bypass headers
-custom cold air intake, not fully completed jet, still sees some hot air when not moving
-OEM TB flipped 180? due to space reasons
-OEM flywheel/clutch
-Harmonic balancer, waterpump from C6 Vette
-Alternator, A/C from ZL1
-Tremec Magnum F MT

Tune is completely stock concerning any tables. Changes made are tire diameter, axel ratios, a changed speed limiter setting (comm error limiter), some DTC?s related to modules not longer present switched off, VATS switched off, volume of gas tank adjusted, Tip in TQ mangement disabled (since car has no analog clutch pedal sensor)

Car is running pretty good most of the time, but I have the following issues/symptoms:

-Flickering MIL, mostly on ideling when hot and not moving or under low to very low load/rpm rolling/cruising.
-Raw noticable jerks when MIL flickering occurs, but by far not everytime the MIL is flickering. Also not under specific conditions, can be felt when rolling, cruising, accelerating or idling.
-noticed constant -13% LTFT at idle

Measures taken:
-Reworked the V band flange between headers and DP (before converters but after upstream O2?s), added a centering ring and a metal gasket there. Before that the MIL flickering was much more present, but even without any DTCs. Noticable behavior of the engine (jerk) as described wasn?t effected.
-Loged some short runs with differnet load situations. Some few misfires were detected on pretty much all cylinders, but count never exceeded 2 and is 0 for all cylinders most of the time. Behavior is pretty much equal in every load situation. Also the misfire counts seem to not have any relation to the flickering MIL. Somtimes there is a misfire detected when MIL flickers, but at least even that often there is no misfire reading. Somtimes a jerk can be felt when MIL is flickering, sometimes not. Only obvious thing is that I didn?t feel a jerk yet when MIL is not flickering.
-Since I was guessing intake air temperature could have an impact I tryed to simulate differnet situations by let the hot car sitting arround ideling for 5min with closed hood. IAT goes up over 80?C. Then opened hood, IAT goes down to arround 50?C in 1min. Then let it idle for 5min more. Repeated this procedure two or three times. It seems that with IAT the flickering gets worse, but no noticable change in engine behavior or misfire counts. (I know I have to fianlise my CAI, a sealing to the hood is still missing. IAT gets down to arround ambient temperature when driving arround 60mph.)

Since this is my very first LS engine and I dont have any expierience with this specific engine and its behavior, there are some more things I?m concerned about, but maybe I?m just over sensitive:

-Little amounts of oil comming out my custom dip stick. There is a bore with a pin to hold the plastic handle with the sealing to the metal stick. There a small amount of oil is blown out. Of course this is caused by WOT crankcase pressure, but I?m not sure if this indicates a relevant issue or if I just need to get my custom made dip stick sealed properly.
-Noticed some oil, maybe mixed with a little fuel, in the intake manifold. Cleaned it before first start after swap what was arround 500miles ago. I would say the amount is one or two tablespoons.

The crankshaft venting system is rerouted but stock besides that. The checkvalve in the line to the intake tube is installed. The line is taking the fresh air downstream air filter and MAF but before the TB. No catch can or something like that. Please, can somebody sease my concerns about the mechanical health of the engine or am I right with thinking about a compression test?

Its a used engine with arround 40k miles on it. Unfortunately had a questinable tune on it before I didnt know about when I bought it. Obviously was running VERY rich and without any O2 DTC activated. I was able to get in contact with the one responsible for that tune and got the OEM tune from him. Did a write entire with the stock tune and started over from there. As I said, no tbales changed. Maybe someone can check if this tune is realy OEM 2013 Camaro SS in matters of all the tables and so on.

Thanks!

PS: Another question is if the few misfires also recorded in the log is a typical behavior for a stock LS car or if this needs to be adressed. To be clear, I want to run this thing as OEM as possible since I need to pass a full emmision test to get this thing street legal. In Germany this means the car will be put on a kind of emmission test dyno and runs a specific driving cycle (NEFZ) where all gases produced by the car will be detected and rated. Any unburned fuel or oil burned together with the fuel as well as marginal failures in converter control will effect the measureings negatively. So I need to get it as perfect as possible...

Tune: Camaro_LS3_modifiziert_V0.2.hpt
Log: misfire01.hpl

[TRStech]

I did another log today. Changed scanner settings, should be a more valuable log now.

O2 B1+B2 seems to operate as they should on my book. Can anybody confirm?

Again had oil coming out of the dip stick tube.

Also a observed a behavior I wasnt able to interprete when shifting to 4th at a WOT pull. (see 13min40s in the "longrun" log) After 4th is in I have close to 100% pedal position, but TP and Commanded Throttle stays at around 50%. Car didnt puul god ofcourse. I decided to keep my foot down and see what happens on the log. After some seconds the TP raised close to 100% again, also power came back. Unfortunately I didnt had TQ managment indicators active in the log, but I can say that Tip In TQ Management is completely disabled since car has no analog clutch position sensor to learn clutch position. Any guess which type of TQ management could cause this or is there another issue I should watch for?

I?m concerned to have issues with fuel pressure/flow, but I unfortunately have no fuel pressure signal on the car. But as far as I interprete the O2 readings engine is running rich in this second, so I would assume that missing fuel is not the reason, am I right?

Please also lay an eye on 26min05s in the "longrun" log. The O2 behavior is changing there while car is accelerating constantly. Is there a exit RPM for closed loop operation or what is the reason?

Also attached a log of the warm up phase from completely cold condition.

On both logs the described MIL flickering (see post #1) is occuring. It Still seems that the lower load and rpm, the more often the flickering MIL can be observed. Pretty much no occurence under WOT. Very intense flickering at rpm near idle and very low load.

Thanks in advance for any help!

o2_01_warmup.hplo2_01_longrun.hpl

[TRStech]

Nobody with an idea? I will have to Pass the emmisions run in a few days. I feel something is not OK. Also fuel consumption seems high to me (17L/100km in a 1300kg car and normal driving). Also the mpg/consumption readings in the cluster are very far of. They Show constantly about 9.5L/100km and it seems it doesnt make any difference how the car is actualy driven. Also current values are not plausible. Party lower values under load, therefore high values when coating.

[blindsquirrel]

MIL flickering, as in irregular or erratic? Or at a steady rate like it's being controlled by something? If it's truly flickering and not flashing, you probably have a ECM ground issue, it's common enough that there is a TSB about it (#06-06-04-046).

[TRStech]

MIL flickering, as in irregular or erratic? Or at a steady rate like it's being controlled by something? If it's truly flickering and not flashing, you probably have a ECM ground issue, it's common enough that there is a TSB about it (#06-06-04-046).

Many thanks, very interessting hint. The flickering has n? stabile frequency. It changes between nothing, once here and there, nearly sratic on... No signs of any repeated sequence or a frequency.

I will Look into that grounding topic. I checked and reworked pretty much the whole harness of that engine, but I remember one factory grounding point which seemed a little suspicious to me. Maybe also I made a mistake with in of the connection. I will let you know about the outcome.

Could you maybe give me a direction concerning my oil leak and manifold contamination? Sealed the oil dip stick, no oil on the engine cover any longer. But Im still a little concerned...

[blindsquirrel]

Have you changed the oil since the rich-running was corrected?

You should be able to find a stock file for whatever you're working with in the repository. Looking at the comparison log feature will show you anything that's different between them.

[TRStech]

Oil was fresh when I 1st fired up the swaped car. It had about 300miles on it when we found a small leakage on the exhaust. Didnt change again for now. Now about 600miles are on it in total. I would try to change it once All the other points are set. Dont think that this makes sence before the flickering and the consumption issue isnt fixed.

Still wondering about 13% negative LTFT when in idle. As well consumption readings are implausible. Instant consumption is jumping between 4 and 16 l/100km when constantly cruising. Only partly plausible behavior can be seen by increasing tendence when rolling to a stop while in neutral. But even then the values are jumping.

Average is always 9.5 to 9.7 L/100km. Feels like the value is nailed there, even when real consumption is 12 or 17 L/100km the reading stays more or less equal.

So I assume a simple % wise adjustment will not be the solution. Im struggeling to find the root cause on that. Is it a Tuning issue (MAF/ AFR /... tables?) or is there still a mechanical issue to look for like another small leak in the exhaust?

To be honest, I cant See anything leaking on the exhaust any longer. But since I have no idea what else could create such a behavior Im still searching again and again. I think I realy need a little help to understand how the consumption numbers are calculated and/or how the flickering might be forced by the ECU intensional. Maybe this gives me a sign where to look for some adjustments, no matter if those are hardware or software related.