Megasquirt Cool, but still smokes after warmup -

[JoeyTheB]

Megasquirt + EDIS in and idling solid as a rock, but not tuned yet.

I still have white/blue smoke after warmup.
Gradually increasing whisps appear after about 3 mins.
About 5 mins, I get a constant stream.

I'm thinking it's coolant related.
Perhaps the heads or intake was cracked on r&r or assy.

Any thoughts before I tear into it ?
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Some observations I've made:

Coolant level - Don't see a change in level, but I'm on ramps in the driveway.

Color - white or blue - definitely floats upward, not super billowy.
Doesn't smell, but I'm not running antifreeze either.

Vacuum test - doesn't act like bad rings - (on acc needle rises)

Compression 160-163 psi warm

Plug condition - sooty black, eventually foul

Tail pipe - droplets of black-ish water. Inside of tailpipe is creamy black - like makeup. After shut off, steamy whisps from tailpipe.

Megasquirt - after warmup, smoking started, reduced REQ_FUEL until engine was sputtering - essentially choked off fuel, still smoked.

No milky oil, tranny modulator ok.

Behaves same with no thermostat.

Water brownish - but that could be from my block.

Odd idea - I had the front cover off, could the oil bypass have gotten somehow mucked up ? Just a crazy idea...

[Takernz_30]

droplets of black-ish water is fine b/c the water and carbon is mixed, brown coolant? needs coolant change but when engine cold, dip your finger in the radiator and examine, if it is oily?

[Mike D]

As far as the black plugs, did you ever install the O2 sensor? If so, then set the EGO tables (look in the manual or on the MS website for instruction, they're kind of hidden) and activate the Automix function through the Megatune fuel set-up. You're running on the "fail-safe" or "limp home" mode otherwise. I went through this with my wife's 250C MS conversion.

What was the extent of the valve job by the machine shop? Did they replace the seals, grind the valves, surface the heads or what?

I'd suspect a loose guide but right now I'm gun shy because I just had it happen to my M110 and I see loose valve guides behind every engine noise.

[JoeyTheB]

Thanks for the reply(s) !
No oil in the coolant - mostly water at this stage - not dark brown, just "brackish".

o2 sensor - Yes!, Just got it in and installed (need to snap some pix).
Found the automix/autotune setting, but didn't seem to kick in when I was just idling on the ramp.

When I first hooked it up, the o2 sensor was oscillating wildly - finally settled down, and was showing me "lean" (not rich as I thought). Oh well, then it acted dead, and I found it covered in soot. Left it out/off for now - will hook back up once the smoke is dealt with....

[GGR]

Steam fumes and water droplets are fine when engine is warming up, this is condensation. Drive the car a few miles and see what happens.

Blue smoke is usually oil, but it smells.

If you burn coolant, you may also have compression going into the cooling system. Is your cooling liquid bubling in the top of the radiator, or in the filler tank, especially after revving the engine?

[JoeyTheB]

Coolant not really bubbly, but it's hard to tell - the upper hose is not far from the cap and there is no "filler tank" - 280SE 4.5

I did pump some air in the driver's side head using a leak down tester.
Nothing came out the rad. Saw this neat video on expert village where they diagnosed a crack block on mustang. They hooked air up to the cylinder and coolant SHOT across the room. No such drama here, though.

[berfinroy]

Have the valve guide seals ever been replaced?

[Mike D]

Extremely rich will show up as "lean" due to the insulating factor of the carbon coating the O2 sensor.

You have two problems and you need to correct the rich running problem first.

Running extremely rich will dilute the oil.

[JoeyTheB]

Good info about running way rich. Got my o2 working last night, will continue to monitor.

re valve guides / head job - Headwork was done by local machine shop that does most of the MB + BMW head work around town. Everything looked BRAND NEW when they came back, including blue dye around the valves.

Are all MB v8 stem seals the same ?
Maybe they just installed what they had in the box labeld "MB v8 stem seals".
You would think they would know being a head specialty shop.... but things happen.

[meltedpanda]

gotta either be coolant or tranny fluid if you have ruled out ( which it looks like you have) other ideas. I had a suburban once with a blown head gasket , did the same thing until one day completely lost the rad fluid on a hwy trip , fortunately for me - winter and I caught it at a rest stop

[JoeyTheB]

Mike D + 1 ! (running rich)

Fuel Pressure Regulator looks shot - gauge shows 60 PSI !
My injectors (Ford high impedance) are rated at 19 lb/hr,
but at 45 psi ! At 60 PSI, they are delivering more like 23 lb/hr.

I used one that looks like this:
http://www.1800philes.com/tuning_article.html

Reset megasquirt with new numbers, and it ran, didn't seem to smoke, but started hunting. Then I saw the pressure had droped to mid -50's.
Megasquirt does not like it when your fuel pressure changes.

Considering one of those adjustable with built in gauge.

Coolant may still be a factor, I'll focus on getting the mixture right.