Need help e39 540i SC reach AFR

[dovlet]

Well, it certainly should help! What are you using for your piston ring end gap measurements?

Never done bro.

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Well, it certainly should help! What are you using for your piston ring end gap measurements?

Never done.

[tptrsn]

But you are installing new piston rings, right? You definitely want to make sure the end gaps are at the correct dimension so they don't but together and ruin your new engine.

[dovlet]

But you are installing new piston rings, right? You definitely want to make sure the end gaps are at the correct dimension so they don't but together and ruin your new engine.

Deamn, perhaps that is the reasson. Never paid attention on that.

[tptrsn]

It's a very important step in building an engine that will see forced induction (any engine really, but ESPECIALLY for forced induction). The additional heat of combustion causes the rings to expand extra, and when the ends butt together, the rings grab into the cylinder walls, breaking the ring lands of the piston, breaking the rings themselves, and tearing up the cylinder walls.

[philly98540]

Dov, as Thad said, don't skip this step. You are at an advantage now to get this gap set correct vs the rest of us with stock gaps hoping we dont trash our motors. This fear is why I got the meth and now the intercooler to keep the ring temps as low as possible. Good luck with the build.

[dovlet]

It's a very important step in building an engine that will see forced induction (any engine really, but ESPECIALLY for forced induction). The additional heat of combustion causes the rings to expand extra, and when the ends butt together, the rings grab into the cylinder walls, breaking the ring lands of the piston, breaking the rings themselves, and tearing up the cylinder walls.

Yeah, will pay attention on that.

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Dov, as Thad said, don't skip this step. You are at an advantage now to get this gap set correct vs the rest of us with stock gaps hoping we dont trash our motors. This fear is why I got the meth and now the intercooler to keep the ring temps as low as possible. Good luck with the build.

Already asked to rebuild engine and check gaps as per instruction in Ring package.

[philly98540]

Gotta go wider than standard gap for FI.

[tptrsn]

Yes! "Build 'em too loose and nobody will know. Build 'em too tight, and everyone will know."

I like to use the largest multiplier that is listed in the specs, always works great:

148354d1419640681-installing-wiseco-rings-general-ring-installation-ring-chart-1.png

[dovlet]

Engine is ready and i drive it to car wash station. Afr was grate 14.7 and everything was good. After washing finished i drive my car to home and realized that it is again become below 10 afr. Sometimes it is trying to come 12 but then again below 10. Opened oil checking sub and full loaded gas to check back pressure assuming pistons cracked again. But nothhing and pistons ring holding pressure.


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I cannot understan what does this engine needs from me...?(((

[philly98540]

You got that put back together and driving already? Superman! Did you set ring gaps prior to re-assembly?

Not sure why your AFR is not correct? What are your fuel trims?

[dovlet]

You got that put back together and driving already? Superman! Did you set ring gaps prior to re-assembly?

Not sure why your AFR is not correct? What are your fuel trims?

Yeah, gaps done. Fuel is 90 octane russian standart. Fuel pressure holds 3.5-4 bars.
Is that possible that my filter does not allow pass enough and injectors cannot sprink?

[philly98540]

Not fuel pressure. Fuel Trims from INPA.

[dovlet]

Not fuel pressure. Fuel Trims from INPA.

Today will check it.

[dovlet]

Morning Gents,

Just made INPA diagnostic and have below video. I do not know exactely but for me looks like some problems with lambda. Isn't it?

[dovlet]

It was good leasson and learnt for me to face with such a problem. Finaly i can say that issue solved. As you may know i have an AFR gauge on my second engine bank which reads driver site of engine. Today done video above where i noted that my bank 1 lambda is working properly and second one is not afr 10. I decided to change their place and noted that afr become 14.7 but exhaust still supereach. That means now lambda from bank 1 & 2 changed and problem started on bank 1. One of lambda is died and that was a reason. Tommorow will change.

[philly98540]

There you GO! Bad lambda = bad fuel control.

[dovlet]

There you GO! Bad lambda = bad fuel control.

Bro, the worst thing is i changed few weeks ago my lambda but nothing changed. I put then my old lambda back. Today when i changed their place i did not realize any thing. Only after all adaptation reset.

[dovlet]

Chnged and reset adaptations. Engine works very well...

[dovlet]

Noted some horse power lose as expected. Drived against a car which usually 3 body behind me after 1km. But now i have a bit more gap against detonation. Also noted that all my power is until 6000rpm. After just loosing power and car does not run well. Any idea?