Hello everyone,

I am in the process of tuning a new engine and new turbo setup and am getting a weird error.

I had my MS running well on my last engine which was a 9.7:1 6-port running a VGT Holset 60mm.
The current engine is a S5 4 port with a GT4088R (Aaroncake )

Running MS2V3.0 on firmware 3.3.3
FFE VR trigger kit.

I used my old Turbo-NA tune and added a bunch of fuel all over the boost portion of the VE map.
Now I'm trying to chip away at the VE map so it actually registers on the wideband. It is off the charts rich right now.

That said, Whenever I go more than ~40% throttle, I get a very loud backfire. I first thought this was due to very rich AFRs smothering spark. But I took a look at the data logs and saw that whenever I'm getting these backfires, I see a spike for Status 2. I'm getting a value of 32 which according to the .ini is "Spark Cut".

I have a Sparkcut rev limit, but I'm nowhere close to the rev limiter
I have a Sparkcut boost limit, but again, I'm no where near it.


Also, I am getting Sync Loss Reason #2 (Missing tooth at wrong time).
I didn't realize this was happening until today and don't plan on tuning under load until this is fixed. I am running a set of non-resistor plugs which hopefully are the issue. I've ordered a set of non-resistor plugs today to hopefully fix this. It looks like it's mostly happening around decel/low throttle but also under boost at higher RPM. Fortunately it doesnt seem to effect AFRs like a Sync Loss # 17 (which I used to get before FFE kit)


Here are links to my MSQ and MLV
MSQ
MLV


Any feedback would be much appreciated

Thanks,
Alex

 

I would think you need to correct the sync loss before you could know what is causing the errors. To me the sync loss is the main source of all your issues. Might need to check for loose grounds or wires .

 

The spark cut isn't really a resultant. The MS is commanding Spark Cut (status2). I am still getting spark cut when I'm not having sync loss.
Hopefully resistor plugs will reduce EMI and get rid of the sync loss. I should have them in tomorrow.

 

Always use resistors plugs

 

I swapped to a set of good stock trailing plugs. Initial impression is that it has made no difference. I'll post a data log tonight and try and capture a composite tooth log.

 

Well, I think my problem is gone for now.
I after changing plugs and seeing no difference, I took a chance and reloaded an old tune and imported my current fuel and timing tables. For whatever reason, I'm no longer getting spark cut or sync loss. The car actually runs pretty well under load! Under light load and decel, not so much.

Current tune and data log:
Link

I'm only getting sync loss when the car stalls now, which unfortunately is often.
The car is also very difficult to restart. I'm not sure if this is a problem with the tune or with the fresh engine that's not fully broken in. This is a typical symptom of low compression rotaries, but this is a fresh engine with only a couple hundred miles on it. Does anyone have any tips to keep the thing running when I press in the clutch? It typically just keeps falling right past idle and stalls. I have to leave it in gear and depress the clutch right before idle RPMs.

 

it will get better as engine breaks in. You can play with idle ve tables and idle timing to try to catch it before it stalls. Every rebuild I have took at least 1000km to get the idle right

 

Looking at the map, a few things will help with the engine stalling on overrun.

First, the idle area of both the VE and timing tables should be a little valley. Then the point at which the engine idles will be at the bottom of the valley, surrounded by a little more fuel/timing.

That way the engine will tend to self stabilise if the idle begins to wander off that point.

Do you have your dashpot? If you don't have the mechanical dashpot then either add it back, or turn on closed loop idle and use the dashpot function to open the BAC as the RPMs drop.

 

Thanks, Aaron.
I will do a bit more work the the VE and timing maps to try and make it more stable.

I used your settings for closed look and it works great for warmup, but once up to temp, the RPM would randomly shoot up to around 3000rpm and hang. I'd pull up to a stop light and get lots of funny looks. For the mean time I set it to open loop idle and found a duty cycle it likes at cold temps. I'm unfamiliar with tuning PIDs, so I need to do some reading and try and fine tune closed loop idle some time.

I also can't seem to find a cranking enrichment value the engine likes when warmed up. It either cranks and tries to fire (not enough fuel?) or floods. The engine only has around 150 miles on it, built with used housings and non-lapped irons. I'm sure it's a bit low on compression which could be my problem.

 

It's going to take a while for the engine to stabilize especially if you have used hard seals (OEM, Super Seals). Plus cold start is the more difficult part of tuning anyway. My general theory for cold start tuning is that once the VE table is decent, just throw more fuel at it in cranking and ASE until it starts consistently, even if very rich. Then back off.

As for hanging at 3000 RPM, make sure the TPS activation point is correct. Increase the lockout RPM.