Slight fog at warm idel

[cody3700s]

Hey guys. I've got a 1985 6.9 naturally asperated, no mods. When I start it cold, it fires up quickly and goes right to the fast idel. Puffs white as soons as she lights up, then quits. After high idel shuts off, there is a very light discreet white/grey fog out of the tailpipe at regular idel. When you rev it, smoke clears. When you let off the throttle after quick rev, it puffs white clouds. Truck doesn't really run ruff. On warm starts, when the truck is too warm to go to fast idel, it starts and runs ruff and puffs white till warm enough to sustain combustion. Checked resistance on all 8 glowplug and they matched out all the same at .005. Do you think she's getting ready for a new injection pump?

 

[franklin2]

Does the smoke smell like fuel or anti-freeze? Have you run it enough to see if it uses coolant?

 

[cody3700s]

Smells like burnt diesel. Almost more like raw diesel. Truck uses no coolant at all.

 

[franklin2]

A wild guess is the injectors are coked and not spraying the fuel like they should. If they dribble and don't spray like they should, the fuel doesn't burn like it should.

 

[dunk]

What's your timing at? Mine had a light/white smoke/haze at times when it was retarded (6.5*). Set to 9* and that has pretty much cleared it up. Also suspect dirty injectors with a poor spray pattern or dribbling, as Franklin mentioned.

 

[square1]

What's your timing at? Mine had a light/white smoke/haze at times when it was retarded (6.5*). Set to 9* and that has pretty much cleared it up. Also suspect dirty injectors with a poor spray pattern or dribbling, as Franklin mentioned.

Is running ATF through the fuel system an acceptable way to clean injectors in place? If so at what concentration / ratio?

 

[OLDBULL8]

Straight ATF. Won't do much for injectors, but will help the IP if something is sticking in it, but gotta fill the filter with ATF, let run for 5 minutes shut off and let set overnite. A little White smoke is normal on a cold engine with a lot of miles on it, cylinder combustion temp, the higher the compression, the less smoke. Try it, ya might like it.

 

[square1]

Straight ATF. Won't do much for injectors

Is there a good method for cleaning injectors without removing them? Yes, I'm aware of the axiom "Fast, Good, Cheap = Pick any two.

 

[BDCarrillo]

The carbon builds up on the tips, which a solvent won't really get at...

 

[square1]

Thanks OLDBULL8 and BDCarrillo for tolerating my questions. I'm experiencing many of the symptoms cody3700s describes so thought cleaning the injectors would be an good starting point.

 

[franklin2]

The timing may be something to look at. Otherwise they do make diesel additives that can help. Like was said you can pour out the fuel in the filter and put the additive full strength in the filter and run it.

Also it's been said before and I have notice it myself, if you run the engine hard(towing a heavy load) they seem to run better afterward. You could also try a different fueling station, one that does a lot of business and their fuel doesn't sit in their tanks for months.

You are not complaining about how it runs, so it must be something minor.

 

[03wr250f]

I talked to conestoga a little while ago because I had similar problems. Mine was I had just recently timed my truck to the baby moose I got from them.(man it is awesome!!!) I noticed I had a little white smoke on takeoffs before she gets warm, and after that it is all black if any.
When I called them up he did say that they are calibrated to run at 140*F Roughly engine bay temp. That makes sense, he said that may be some of my smoke but I have poslished **** injectors from dcp...which I had go out once before. It has a slight clatter before she warms up and its funny its the same quiet clatter it had the last time dcp injectors went bad. I just haven't had the money yet to buy new ones. Either way once she warms up she runs like a top. I just know I need new injectors here soon so until then I make sure to let her warm all up.
Just food for thought it may also be injectors starting to go south.

 

[cody3700s]

Thanks guys, I'll throw a pressure matched set of code BB's in her and see if that helps my idel fog, I'll also advance the timing slightly to see if I can get a little extra clatter out of it. I like to run my idi's just slightly advance. Seem to have a little more power that way.

 

[franklin2]

Thanks guys, I'll throw a pressure matched set of code BB's in her and see if that helps my idel fog, I'll also advance the timing slightly to see if I can get a little extra clatter out of it. I like to run my idi's just slightly advance. Seem to have a little more power that way.

Be careful. I have heard some talk on here that running the timing a little too advanced can burn the tips of the glowplugs off and they fail.