OK Guys.

I started a thread earlier, but it got like 13 views.

So, I'm starting a new one that comes with a video.

My problem is smoke on winding down of the engine. Not during high rpm, just while downshifting and coasting on occasion.

A few points you must know before watching:

- The cloud appears thicker due to the lack of quality of the camera
- It took me numerous tries to get this shot. My problem doesn't always show up. Sometimes if it does, it's barely noticeable. This was the best of them all.

Take note of:
- The car is fully warmed up
- The car is cat-less. Repeat. Cat-less.
- This is a rev all the way to 7200 RPM.
- the smoke only appears or begins to appear AFTER I let off the gas. This is the KEY point - or at least the key point I'm basing my theroies on.

(please wait for it to fully load. It's not big. Perhaps you should watch it 2 Times after it had loaded to ensure proper sound / picture timing. )

** Video **
http://members.rogers.com/thecheat/smoke13b.avi

Theories.

1. MOP problem.
Due to the fact that it doesn't happen on command, and only happens during a down-rev, I believe it is an MOP problem (dumping too much oil into the housings after WOT). It rarely happens, and this video is the worst is has ever happened. Comments?

2. Unburnt fuel.
I am aware excess burnt fuel is Black, not bluish. However, that is what happens to totally burnt fuel inside the engine. I'm talking about unburnt fuel getting burned up from the heat inside the exhaust. Would it still be turning black? I think the partially burnt fuel in the exhaust could make a different colour. Obviously, as with any theory, I could be wrong.

-----------------

I do not believe this to be a sideseal problem. The car's compression is rock solid. I believe if it were a sideseal problem, this would happen consistantly at high RPM, and also it would be during a wind up, or WOT, not AFTER WOT (aka wind down).

Again, I may be wrong. If I was so certain I wouldn't have even started a thread.

I'm coming here for more expert opinion. Maybe someone can point me in the right direction.

More things to know:
I have attempted rolling at high rpm, it had smoked 1 time at high rpm. That was roughly 1 month ago. After more testing and testing, it has yet to do it again. I believe when it happened it was a fluke.. I may have accidentally let off the throttle entirely during that test. Either way, this would relate to MOP response, wouldnt it? The smoke on that occasion was more blue than anything. Anyways I have done it a few times for more testing (more accurate test than my last) and it had yielded NO smoke.

The only smoke I ever get is what you see in this video.. or during a coast, and i let off the throttle to wind down. It will again do it on occasion and is seemingly random.

That's why I'm leaning more towards a faulty MOP mechanism than anything else, because of the randomness both when it happens, and how bad it happens.

Thanks for your time, Guys.

-Colin

(btw - my unburnt fuel theory, is just that. a theory. I'm leaning more towards burnt oil, but it was just something I felt I should bring up.)

 

Alright, you're safe in your assumption it's not the oil seals, I know what those look like. It definatly is oil though, and it's seemingly a rather quick burst. Check your OMP linkage and have someone just floor it and let it off real quick and see if it gets stuck in open position for a split second, or of it seems slow. Oh, and also, you don't have to have the car running to test that.

 

The metering oil pump is evil. Crankcase oil does not belong in the combustion chamber. But the American public would have nothing of having to top off a two-stroke oil tank at every fill-up, the designers reasoned (probably correctly).

Well this is a bit off the topic. My hidden agenda is to convert you to premix.

 

Hmm what ever happened to Mr. Cake and his long response???? After RETed posted he never came back.


Santiago

 

SonicRaT - I have just inspected my Linkage / MOP components. the MOP itself (down by the pan) is a little bit dirty with oil..

I found a spot on the throttle for the MOP arm to get stuck at it's maximum output. BUT, it's beyond how far WOT can push it. So if this is the case, it must be getting stuck somewhere, and then being pushed up a tad higher than normal, at which point it gets stuck until you blip the throttle.

I'm going to take a stab in the dark and say engine vibrations could both assist in getting it stuck, and getting it UNstuck. Hence the randomness. The linkage feels like it has enough play for the engine vibrations to possibly have some sort of effect.

.. Or am I making wrong assumptions - the MOP linkage has roughly an inch of play without touching the throttle. It's tough to describe the play in it.. should i make a video of the linkage play and show it to see what you guys think?

88IntegraLS - Funny you should mention this. During the MOP test, I thought "I wonder if i can disconnect the MOP linkage, and run a tank of premix just for 1 time, to see if its makes a difference in smoke on downrev."

Would this work? or would the fact that the MOP would always be reading/giving 'Idle' amount of oil to the housings ruin any conclusions I could come up with on a tank of premix and no MOP linkage?

I Appreciate the insightful input guys.

 

Hmmm

You are saying to leave the MOP there but no linakge and run pre-mix??

 

Just as a test, to see if it makes a difference in smoke on wind-down.

i realize the MOP would still be injecting oil, but a very small portion, right?

 

why not just throw away your MOP?

 

As I stand right now I am not too interested in ditching my MOP.

I have read, and re-read, and re-read your thread (especially examining RETed's points).

However - If i conclude my MOP to be failing/failed, then i will be removing it and running Pre-mix. Only due to the fact that silverrotor has been running NO MOP and premix for sometime now, and his engine is smooth and has never had a problem (with lubrication that I am aware of anyways).

BACK ON TOPIC THOUGH!

Comments about my MOP linkage? Can I try this dubbed 'Pre-Mix Test'?

 

Been through this before. Anyway, run without the linkage & premix to see how it goes.

 

In my situation? If so - please share.

.. Or are you referring to 1987RX7Guy hijacking and trying to get me over to premix?

Comments about the Linkage play? You still run MOP, SonicRaT?

 

Commenting on the thread hijacking. And yes, I've still got the OMP, let me go check the play. How exactly where you finding this play?

 

I measured it. I am slightly mistaken when I talk about the play.

Before there is any resistance to move the MOP linkage, it moves freely up to 1/4" past the support tooth on the throttle linkage.

it continues to have 1/4" of free-play past the support tooth all over the throttle.

at WOT, if it is 1/4" past the support tooth, it is stuck (in maximum output).

but in this situation, there isn't really anything to move it that extra 1/4". At least that I can currently find. I could be missing something that might push it that extra 1/4".

understand what I mean? or should i take some pics or something.. when you look at your MOP linkage at the throttle, youll notice what I mean. that support tooth is holding the linkage from falling down.

 

support tooth? On mine there's a dowel with a hole in it that the linkage goes through and there's a pin that holds it in place, I'm a bit confused, lemme go look.

 

Mine is the same, but that dowel/pin has a little plate that rests on said support tooth. Have a look see.

edit - I see you have an S5. I'm curious if its different between series? Or are you checking on an S4 vehicle?

 

Well, at WOT I have no play whatsoever, I can't move it at all. and I can't move it at all where there's any play. Are you sure your linkage is hooked up properly?

Edit: I've got both a s4 and a s5, going to check the dowel pin's 'tooth'

 

My linkage may not be properly hooked up / tightened. I'm not sure how to go about that. Perhaps I can attempt to fix it if you could guide me in the right direction, and post again if it made any difference in smoke.

 

Aha, is the tooth you speak of the catch for the throttle linkage, that the OMP linkage rests upon, so when the throttle is pressed it raises the omp linkage? Mine rests on that plate all the time mine can't get stuck in any position, no matter what I do to it, and there's no play anywhere that's resistanceless (though it is a small ammount of resistance)

 

Well, mine has two washers, then the pin on the bottom below the linkage, and then it goes straight up through that dowel there, so I'm not sure how it can't be hooked up right. Spray the **** out of it with brake parts cleaner/carb cleaner, move it a few times to try to free it up and try again, if that doesn't work, disconnect it and try premix and see how it goes.

 

Thanks for the info SonicRaT.

Can you move your MOP linkage up and down on the throttle linkage without moving the throttle? that may also be my problem

It's lose enough that if i push the linkage up with my finger, the throttle doesnt move, just the MOP linkage up and down.

.. If that makes sense..

 

um what just happened here, im lost!! =(

 

What the crap are you talking about?! Read the thread!!

Makes sense to me..

 

Can anyone guide me as to the proper way to tighten the MOP arm?

 

Yeah mine moves freely like that as well.

 

hmm.. I think I may disconnect it and try the premix then..

What components are made up of the MOP?

What else regarding the MOP should I be looking at?