possible timing issue?

[pwjackson]

Got a NA 6.9 with complete new fuel system. I have noticed when driving that I get nice black coal smoke at low rpm but when I get in the 2500 to 3000 rpm rang and getting on it down the road I have a grey smoke. Could this be that my timing is to far advanced? I have been getting around 15 to 16 mpg so I figured it was timed pretty close. I had a well known shop time it for me, didn't know that if with the low sulfur fuel and the slightly advanced over oem timing would cause the lighter smoke at higher rpms.

 

[icanfixall]

What exactlly is your completely new fuel system.... Who rebuilt the pump and are the injectors new or rebuilt.So you don't have a turbo. Ok... The black smoke is not really an issue.The grey smoke tells me your getting more air in the engine to burn the fuel being injected. What was the timing set for and how was it done. Really only one way to time these engines is accepted around these forums.Thats the pulse method. By far the worst way to time is by ear but many have to do it that way. The luminosity probe method is another way to time but you need to remove the number one glow plug and insert the probe.Then you need to know what the cetane rating id for the fuel your burning... Cetane is the same thing as octane for a gasolene engine.

 

[blown84]

im gonna guess that your grey smoke is a combination of engine speed and vehicle speed. as the engine turns faster, it pulls more air, and really, the IP can only put so much fuel in the motor. secondly, as your vehicle speed increases, the more your nice, neat cloud of coal gets ripped apart by the wind, makin it look more grey instead of black.

mine does the same thing.

 

[pwjackson]

I have a rebuilt pump from Columbus Diesel in Columbus OH and the injectors are from NAPA. The shop timed it with a meter not sure which kind. I mean it runs fantastic and has all kinds of power. I just didn't know if the greyish smoke was do to it being to far advanced because I know that can eat your glow plugs.

So what you are saying blown84 is that I need more fuel No, really I just wondered if anyone elses NA truck ran the same going down the road. I would like to find someone else to time my truck with a meter just to see exactly where it is so that I know for sure.

Also I run a blend of WMO in the summer time, should the timing be retarted slightly for this?

 

[hesutton]

You said the IP timing was set via a meter......... what was it sat at and if I'm reading correctly, it was changed after it was set??? Correct?

Did you pop test they injectors before instalation to ensure they were good? A leaking injector or two can cause excess smoke and piston damage.

Heath