Emmision troubles

[Dodo Bizar]

Just to inform people with similar situation:

I have an B16B (next to the D14A3) for 4 years now. And each year I needed some squinting with the eyes to pass MOT. Never really wanted to talk about it (something with re-sell value of the engine), but since I can't get myself to sell the engine and car anyway in this condition, why not share my problems.

Here it is, I have always had too much CO (0.3 to 1.5% on diverging rpms, circumstances) together with unburned fuel and unburned O2. So flame dead. Tried many many things, very elaborate ECU tuning, cilinder switch off to see if there is one cilinder causing this or all (the answer is all equally bad). Tested for compression, changed valve seals, changed head gasket and things only detoriated over the years.

Now I removed the pistons... cilinder walls are like mirrors and piston rings are gone. Completely worn out. Talked to some expert today and they pointed out to me how a new ring should look like and a ring that is up for replacement. Mine was way worse than that. So I'll get a new cilinder hone, piston rings in the engine and hopefully that is the end of it.

It has to be because all else has been tried and/or excluded. But the most disturbing is the fact it does not use that much oil. Easily 4000 km before it needs 1 liter. Depends on driving style, on the track I loose an entire liter within 2 hours... but that is track. That was why I was looking to the wrong direction for years.

I know that exhaust valves are black from oil since last year (I did head gasket change) and I have carbon deposits on top of the piston. Which points to oil. Since I replaced valve seals and yesterday I saw that both upper and lower blocks are silver from the inside (extremely clean, especially compared with my exhaust fumes) there is only this mechanism I believe in:

- piston rings are gone
- oil is forced upwards
- but oil is not forced downwards
- oil burns in combustion chamber during low throttle (95% of the time or more)
- oil deposits cool down or change burning, extinguishing flame at the valve and combustion chamber boundaries
- leading to very nice bhp (203 on 1.6 liter)
- but leading to unburned mixture both O2 and HC... which I guess is normally burned closer to the walls and after exhaust valve in good engines

I never gave up on this engine because I really want to learn from it... throwing an engine away and buying a new one is not learning. Hopefully I can inspire others to continue bug fixing their engines or maybe help identifying this problem for others.

[007]

a B16B should *never* be thrown away! I am sure she will be perfect after a rebuild. glazed rings / cylinder walls are never good news. did you also happen to check compression before you opened the engine up Joris? I think that in addition to consuming oil and lowering your effective octane rating [and thereby demanding retarded timing, causing unburnt fuel to escape through the exhaust], your compression was also lowered and the engine's efficiency took a hit.

a proper rebuild as per factory spec should sort things right out.

[saxophonias]

So bad emissions but not underpowered Any other sign of not smooth working?

[007]

it is a Type R engine. it would be a surprise if it *didn't* make power.

[Dodo Bizar]

Fuel economy was incredible good, 14.8 km on one liter on it's last tank! Ok that is only highway, but for a B16B I guess hardly no one has ever managed that. I did test compression once, it was between 13.5 and 14.5. I believe a compression test does not tell this. My guess is the rings still seal fine with respect to gasses. It's the oil film on which it now is aqua planing. Due to the compression test results I was reluctant to open up and change rings. And it is also therefore I make this post, to get this awareness... I guess.

Ignition timing was factory values, nothing had to be changed there, tested it on dyno.

The basic idea of this post is... the symptons did not add up to to what is generally believed and told. Compression was and still is fine, oil consumption not extreme, fuel efficiency like a charm, etc. etc. But still something was wrong with cilinder walls and rings.

[sktaroins]

Joris, I remembered something called motorup extreme.
Its a liquid form that catches on the cylinder wall allowing frictionless movements between the pistons and the wall.

Im not sure if it will keep oil downwards but im sure that this lubricants can last 30,000 km even if the gas or oil run out.
I installed it to my car after the rebuilt and the erratic noises of the engine calmed down.

I got it from thane ....something ill get u the link soon

- so today is 16sep came back from 12hrs work and i got on this but i cant seem to find the video where they test 12 football players on an egine running with motor-up extreme and no oil ... and engine still running ..

however ill keep looking ...

for now those are what i found the closest for you joris and saxo and you too 007- it really works

http://www.youtube.com/watch?v=FfuTPHzmlG4

http://www.youtube.com/watch?v=xz5tftUW ... re=related - in german though

http://www.youtube.com/watch?v=5vBc2n8qjR4

http://www.youtube.com/watch?v=4tyxcF8E ... ure=relmfu

----

ill see if i can get the link where they give you fuel system cleaner and transmission -- i mean the whole package for around 57euro ...

ill get back to this post and edit it

tc guys

[hondamake]

Hi Joris. Don't ever forget the mantra "common things happen commonly". We all know how tough and reliable every aspect of a Honda engine is. Indeed it is this quality that makes them go far further than most others and also means that piston rings and valve guides (which are wear items) are subject to super high mileages. If it was a Renault engine it would have been scrap at half the miles of your B engine, because it's a Honda it will be as good as new with a relatively cheap overhaul. It was ring wear at 180,000 that led to me replacing my D16Y7 with a D14A4, but I've kept the D16 for future use.

[mynameisowen]

Have you replaced the rings and honed the cylinders yet? I want to know if this sorted it out

[Dodo Bizar]

The answer is I honed and changed the rings, but emmisions still suck.

But, there is a but...

First the result of the rings, it does help with my blue smoke, I have not seen any blue smoke coming out of the exhaust when revving it up, releasing throttle, keep revs high but let engine brake, and then suddenly put throttle on. In the past this has been a way to anoy tail-gaters, but it seems I did solve some problem.

But emmisions, they stayed bad as usual. Up to 0.9% CO on idle. But, and now comes it, I had driven it around for 5 minutes to make sure the engine had some heat. Then I pulled it in the garage, put the emmision tester in it, and first CO raies to 0.17%, after which it went DOWN to 0.00% and it stayed there for several minutes!!!! Even my MOT guy has seen it. Then he asked me to apply some throttle to test at revs... there CO% went high again, over 1%. And now the surprise, when going back to idle, CO stayed out at 0.9%. So MOT guys helped me to get passed since this was the only problem (where would the world be without an occasional squint of the eyes) and I am confused.

And then I remembered from my very first MOT with this car three years ago I got the exact same story from those guys, that it was ok for a short while and then got back-tracked.

Soooooooooooo the nightmare continuous. And know I start wildly guessing. Maybe I have a very weak open in one of the injector wires. One that does not make an injector stop, but one that makes the opening time different from the other three. Note that I have changed the injectors for a new set already, so that is covered and not the problem. First thing I'll do is simply change out the engine loom for a complete new one. Have one lying around, just have to do it... only menas I have to miss VTEC for a while since it is a D15B7 loom .

And also here I apologise for being offline for so long.

[mynameisowen]

Welcome back

Hope you can sort it, how are spark plugs? AFR? CO is product of incomplete combustion so too much fuel or not enough air.