[CEK Garage]

Just doing youtube videos doesnt make me right or smart. But I do like to help out when I can. And this is close to an issue I had a few years ago from the sound of it so far.

[jonbill]

sounds like a small air leak to me.

[Seke]

I changed from standard injectors to Siemens Deka 630cc, Walbro 450, but I also changed engine and mounted turbo

I will do a smoke test in the week to check for air leak.. If I can't find any air leak it must be timing problems as Pazi88 mentioned.

But it seems like the speeduino isn't a source of error for my problem?

/Andreas

[Seke]

Went for a short drive now.

It goes really lean and at 3.5k rpm and 0.3 bar of boost the ve is over 200 to keep it at lambda 1. Will tear appart my engine and check the timing. Feels like something is going on with the engine and not a vacuum leak..

https://drive.google.com/open?id=1q0iVn ... _u8tV65-TL

[PSIG]

Seke, post the exact tune used to take the 2019-09-07_16.42.37.msl log. I can't see what Speeduino thinks it is doing without it. I wish I had time to look at entire running logs, so I jumped to the max MAP found in the log (boost threshold pull between 226 and 234s), where there is an issue with lambda vs AFR reporting. Reported AFR (assuming 14.7 relative gasoline scale in your setup?) remains between 10.7 and 12.5:1; but lambda reports 1.09 to 1.28. I can ask your TS settings for this run, but it's much, much easier to load your msq.

While we can bench test with voltage input; I would ask that you do some other verification of relative lambda so we do not assume which is correct, and so you may continue tuning. Also, provide some log time points for specific events to help guide us. Tagging @noisymime to take a look at this, but having the matching msq for this msl would be first so we don't chase squirrels.

David

[Seke]

I'm running E85 and stoic value 9.8. I have attached the MSQ and a new log file.

If you look at 60 to 65 seconds my problem occurs. Even 80 to 85 seconds. It doesn't matter what rpm.

Log file
MSQ file

[PSIG]

It goes really lean and at 3.5k rpm and 0.3 bar of boost the ve is over 200 to keep it at lambda 1.

That's better. It appears a settings change has corrected the readout and you're not going lean (by data indication).

So now back to your stumbling, which appears similar to dropping a cylinder. While it could be anything at this point (always keep an open mind), I would attempt to isolate the issue. For example, when it is held running rough, check the exhaust headers with an IR temp gun to (hopefully) find one that is dropping and causing the jittery readings.

If that isolation is successful, then you can further focus your attention there, first checking everything mechanical (valve seal/lash, timing, spark plug(s), manifold seals, leak-down, etc) and electrical (spark, timing, ignition coil(s), wires, connections, injector(s) etc) that impacts it.

Good luck, and if you take this path report whatever you find … or don't.

David

[Seke]

Hello!

Has since last time retimed the engine, thought it was a bit off, but it wasn't. I have changed FPR, checked spark (but the hardware test didn't work in Tunerstudio). I have tested the injectors and they flow similar. New fuel filter.

I have also checked for vacuum leaks again and again, but nothing. The original breather setup is plugged. Bought new OEM crank shaft sensor from BMW dealer. But still the same.

Tried taking temperature with IR-gun on manifold, and cyl1 is always much colder than the rest. Maybe because of less heat from the other cylinders, or is my problem there? When other cylinders reads 200 celcius number one is around 100. New spark plugs and tested many different coils.

Compression is good and equal on all cylinders.

It will start to run fine with just a tiny bit of load. Was out tuning today, it ran good until it suddenly started to misfire at all load. Stop for 10 minutes and then tried again, now it worked? I'm out of idéas again

[LPG2CV]

Sounds like an intermittent electrical fault! Check 12v supply to injectors, and connection back to speedy. Then check likewise with spark. Check all gnds are good. Check speedy 12v connection and fuses are sound and clean.

[Seke]

Thank you. Will try that.

When I am tuning the ve cells att 0.3bar and 3500-4000 rpm need to be at over 300. Isn't that any sign of a problem? Or is it "ok" with that high numbers?