*intermittent* black smoke

[sask3500]

Tonight I ran the truck into town and got heavy black smoke under acceleration to speed and then smoke if I roll on and off the throttle. Once I got to town, it turned to a puff of black and cleared up. Fueled up and checked the wastegate solenoid. It moved as easily as if the truck was off. Smoke came back for a bit and went away for a bit alternated all the way home, solenoid firmed up when I got home. No codes stored, no check engine light under any conditions.
Am I right to assume the vacuum system can fail intermittently? Or is it possibly an electric issue? Any and all input is welcome.

Edit: the wording should be: what parts, mechanical or electronic, can fail intermittently to produce an intermittent overfuel? I am only assuming the boost is coming up short due to the (one time) loose solenoid. Not alot of hard evidence.

Justin

[rustyk]

Check the air filter...

[sask3500]

Yes I will. Definately. But it is less than 5000 km old and looked sweet at the last oil change, approximately 100 km ago. I will check it out though.
I am looking for ideas as to why there would be an intermittent symptom.

It either blows black smoke while accelerating, or it behaves normally with a little smoke from a stop or a stretch of neutral throttle that clears up immediatley. It is very black and white, on or off.

Justin

[Robyn]

Sounds like an issue with the vacuum to the wastegate actuator.

Be sure you have 26" vacuum at the pump and at the inlet to the control solenoid on the LH valve cover.

With the engine running there should be 15 inches or so of vacuum at the wastegate actuator and the rod should not be moveable by hand.

A failing vacuum pump can cause this issue as can a failing/failed waste gate solenoid.

The solenoid is on the LH valve cover and has the vacuum lines running to it.

Be sure the lines are not cracked or loose.

To check the vaccum pump, hook a vacuum gauge to it and see what it does.

If the gauige flutters all over, the pump is shot.

If the Solenoid is shot, it may or may not send a code (SES LIGHT)


Let us know

Missy

[sask3500]

Sorry for the slow update, we just had our second little boy come into the world.

I have not tracked down a vacuum gauge, however I did fiddle with the ECT sensor wire, unplugged it, straightened it, etc. I never twigged on to it but the glow cycle seemed long as of late. I had unplugged it in really cold weather to get the truck to start and it may have a bad connection from the old wire/cold weather flexing combo.

Would this be related to black smoke with the timing being retarded? What damage can be done if it's driven with no connection to the ECT sensor?

I plan on checking the vacuum system too, but thought I would ask.

Justin

[sask3500]

Any advice? And a reccomendation for a manual with more detailed diagnostic procedures for the 6.5 would be appreciated. Things like how to tell if the ECT is healthy, etc...

[sask3500]

So I got ahold of a mity vac, cool little thing that is, and have 17" at the wastegate and 19" at the solenoid from the pump. It vibrates between 18-20". The wastegate actuator arm IS moveable with finger pressure, but it's work. And I run a very big sandblaster for a living.

Other factors may include: I need to change the t-stats as they have failed open. Truck runs cool.
Condition of the timing is unknown. Need to get it checked and set.

So...What say you?

Questions, suggestions?

Justin

[DmaxMaverick]

I suspect you have a vacuum leak between the pump and valve, or the pump is failing/failed. 19" is too low (should be 22" minimum, 25" optimal), and you should not be able to move the WG with you finger. This would explain your black smoke....If you can move the WG with your finger, the exhaust back pressure will overcome it at too low boost. While 18-20" of gage fluctuation is not excessive at idle, it is a maximum, and may be indicative as well, being you were not measuring at the pump (the plumbing should buffer this to a nearly zero variation). Measure the vacuum at the pump outlet. If it's the same or more (with no more than 19-20"), the pump needs replacing.

[sask3500]

I will check it at the pump tonight. Thanks dude.

[JohnC]

use the mity-vac to apply 15" of vacuum to the wastegate actuator. It should be leak free and very difficult to move.

Like Dmax said, the pump should supply 20+ inches to the solenoid and it should be steady. The solenoid should supply 14-15" to the actuator at idle.

[sask3500]

"use the mity-vac to apply 15" of vacuum to the wastegate actuator"

Genius. Will do that too. Maybe. '89 Freightliner conked too. That's a bigger issue.

[sask3500]

Problem "solved"! 17" at the actuator, 24" at the pump and solenoid, leaky line shortened to fix it. But then I snapped the inlet off the solenoid and phoned all the places in town. Last place will get one here 600 km overnight for the best price in town.

The 89 Freightliner is home and running, 99's clutch is no longer slipping, it's front tire is patched and I didn't skin one knuckle. Phew. Suppertime.

Thanks for the help.

Justin

[JohnC]

I know it's tough, but you could always ride the bike... ;)

[sask3500]

JohnC: I make every possible excuse to. Like picking up parts tomorrow. Reliable as a hammer too. Handles a bit like a hammer, come to think of it. It'll smoke your trumpet though :-)

Justin

[JohnC]

IIRC, when that bike first came out it had the fastest 0-60 time of any production vehicle anywhere. (4.0 seconds). Friend of mine had one. I don't know how we ever survived...

[Robyn]

All the plastic pieces just don't do well over the long haul in the underhood heat.

Glad you got it sorted out.

Missy

[sask3500]

So I got the solenoid swapped today, warmed it up and it has a little haze of smoke under WOT but not much. Does anyone have good or bad comments about the boost fooler that kennedy sells? Will it increase boost throughout the rev range or is it only peak pressures? Any good DIY links?

And yes the kawi alternates spinning back wheel and floating front, whenever it, not the rider, feels like it. I also ride it on dirt roads around the farm, those are exciting rides. Corners take FULL commitment and attention.

Justin