Well ive pretty much removed most of the OMP components on the new S4 T2 motor but the quote from RE Teds site still crosses my mind regarding no/very little lubrication from the fuel injectors under deceleration. Should this be a major concern? Any input from those running premix only would be appreciated. With replacement of the blown motor not too far away, the last thing id want is to blow this one also because of lack of lubrication. Thanks in advance.

 

Shouldn't be a problem.

Hey, I drove for 2000 miles with no OMP, being "unkind" to the car, and I suffered no problems. I do not know how long the previous owner drive it like that, although I did find a can of starting ether in the back!

Engine ran strong for another 30k before I pulled it for something with a bit more port.

In short, don't worry about it!

 

how many seconds do you spend one decel at a time? 5-10? its not a problem unless you are coasting down a mountain or something

mike

 

I see. Thanks for the additional feedback.

 

even 5-10 seconds won't be a problem.

technically the OMP isn't even needed. Mazda added it for longevity reasons. Coasting is about the lightest duty the seals will ever see, so it ain't a big deal.

 

Believe it or not, gasoline is actually a mild lubricant in itself. This is why cars have the fuel pump submerged in fuel, to lubricate it (no kidding). Although I don't know if the fully atomozed fuel / air mixture inside the engine would act like liquid gasoline, but I doubt any fuel injection system atomizes the fuel 100%. Perhaps, then, there would be small amounts of liquid fuel, fallen out of suspension in the air charge, left on the inner trochoid surface from centrifical force.

To make a long story short, there is probably still residual fuel on the intake section of the rotor housings for the seals to slide on during deceleration.

 

Thanks again guys. Sealed off the OMP today. Almost ready to put the new engine in

 

actually fuel pumps are submerged in fuel more to cool them than anything else

 

The 2 stroke oil you use when you premix actually doens't just magicly disappear from the housing under de-cel, even after the combustion cycle is done, (some of) the oil will still be there to lubricate the housings.

 

I know on the 13b fuel is still injected during decel. an easy way to test this is to be driving, put the clutch in, and watch the revs drop. Do the same thing, but turn the key and it'll drop faster.

 

You haven't got that wideband operational yet?

I beg to differ. Up for a friendly argument?

When I was dyno tuning a while back I remember this being brought up when the tech. saw the decel settings on the safc. We confirmed that the injectors cut off completely by watching the a/f ratios go to to near pure air when you let off. He was like "OK, fuel gets cut on decel, lets move on".

My guess-O-meter a/f gauge shows full lean with no bars lit also.

 

No, I haven't. Haven't you seen my turbo? Where do you think the wideband sensor money went? And I just got kicked in the *** by my tuition bill for this summer (flight courses). It won't be running for a little while.

 

Ouch, that's right, your compressor wheel got mutilated. Sorry to hear it. So you've got the WB kit but no sensor?

 

yeah.