Hi all,

I have quite a bit of smoke on cold start ups. With my setup, I expect it 100% but thought I would ask the question for those who have quite a bit of knowledge as to whether there is a way to somewhat reduce it. For the street, it can be a bit much at times.

Main mods:
Street port
t04z
2000cc x 4 injectors
2x 460 walbro intank pump
E85 with premix - 100ml per 10 liters (Recommended by manufacturer)
PFC
Safe tune (a bit rich)


Here is a video of a cold start

Sometimes I get a puff of smoke on initial startup when warm if it sits for 30 odd minutes.

Any input is appreciated.

Thanks

 

The short answer is, you don't have a lot of options.

These engines have poor sealing of the combustion gases and oil. Mazda recently released an SAE paper explaining this; it is due to Warping of the side housings among other thing, due to old manufacturing methods. They are actively researching a solution.

Age of the engine makes it worse.
Rich mixtures give more fuel to blow past seals and smoke.
E85 inherently burns poorly when cold. Did you know that OEM flex fuel vehicles are exempt from the EPA and CARB from meeting emission standards under 75F conditions when on E85?

You can reduce after start fuel (water temp compensation) and cranking fuel in the tune, but you are now risking poor starting and after start stalling. Art cutting cranking and after fuel start down, until you run into this problem, and then put fuel back inext. That's a long and tedious process with no guarantee of significant improvement.

Other options aren't realistic, like buying a brand new engine from mazda, opening it up and clearancing to tighter spec.

 

I'm seeing simple condensation "smoke". Yeah, there was a small blue puff initially (all FDs do that) but the white "smoke" is not smoke at all. Very normal.
What was the ambient temperature when the video was shot?