Blue Smoke????

[AlK]

Over the last month ( two tanks of fuel) I have noticed that immediately after starting my truck while cold it spews out a fair amount of blue smoke (outside temperature is well above freezing 40- 55 F. ) Once the truck is warm the blue smoke disappears and only black smoke is visible if I step on the pedal. The truck starts well, runs smooth and burns no oil. I purchase fuel from the same local station that sells a lot of diesel to large trucks and busses. The smoking seemed to start with my last fill up from this station. Since then I filled up once at an out of town location (same brand name). I add stanadyne to the diesel. Any thoughts as to what is going on?

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92-LE,4x4,5spd,3. 54,Borgeson steering shaft, Tach,Isspro Pyro & Boost, 16cm2, PW injectors

 

[Old Nordby]

Is your grid heater cycling? I see gray/blue smoke when my heater doesn't cycle, only on startup. I get a fair amount going downhill in 4th just above idle on the gas pedal, only when cold.

Another potential cause is air, but you're stating your truck runs fine and the power is normal.

jon

 

[BushWakr - RIP]

Hi Al,

I noticed that same situation but ONLY after I made the injector change and pump adjustment. Afterward I had the pump timing adjusted upward a bit (to about 1. 37mm) and that seemed to help quite a bit. It did not totally elim. the blue/white but it now only happens when its cool/cold. In fact I still have a tiny bit even when using the block hearter. After a couple blocks I don't see a thing.
Have you had your timing properly set? There is a good way and a best way to do it. Check out the site with a search on proper pump timing.
Hope that helps put your mind at ease.

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93. 5 W250 4X4,HD Spring Pkg, Rancho 7000's, Rear Swaybar,Dual Shock Front Stabilizer,BD Injectors,31/2" Mandrel bent exhaust,16cm 'Hot End',Modest Pump Tweaks/Timed,K&N Air,Isspro Pyro,Tach,transmission Temp,Auto Meter Oil Filled Boost Ga. , 3:54's, 4 Speed Auto, Clubcab, Aftermarket Reclining Buckets w/ctr Drop Down seat/console, Black over Silver, 21psi,285-65R-16's,American Racing Clear Coat Mags, Amsoil 15W-40HD Marine,12,000 lb. Warn Winch,KC Spots. 101,300 Kms (63,000 mi's).

 

[AlK]

nordby, the grid heater is cycling and the KSB is energized when I turn on the ignition key. Your suggestion about air in the system may be a possibility. In checking back over my maintenance record I find that I changed the fuel filter approx. 200 km before the blue smoke started. I will bleed the system for any air. The service manual states to bleed the system only when the engine is cold and to be very careful not to let the pressurized fuel touch the skin. I have not done this before, but it would appear to be quite simple, so any other hints or suggestions would be appreciated.

BushWakr, I am assuming that you used the services of VFI for the pump timing?

 

[Lil' Dog]

I too have the blue smoke when cold. I will have to inspect the lift pump connections and investigate the air thing. Good idea, Mine is also a little rough idling until I can get her warm.

J-eh

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Jason Hoffman
Lil' Mack - 89 D250LE 5 Spd 3. 54 LSD Reg Cab. K&N,"tweaked pump", BD Injectors, Banks Pyro/Boost, 3. 5" Exst tail section straight. E&M Custom seats. Bosch H4, PIAA 80W/80W HdLites. 100W Drv,55W Fogs.
237,500 miles (380,000 Kms) 7850 Hrs. Cummins Power Booster member.
The Original Turbo Diesel

Lil' Mack Pics/March 2001

 

[BushWakr - RIP]

Hi Al,

Actually no, I did not use VFI. In hindsight I should have I guess. The shop I used is in New Westminster, (email me and I'll fill you in if you like) and is close and friendly place. They however use the timing pin to set.
I watched as they did it and a great amount of time was spent to make that method as accurate as possible. When done I was told that the timing was about 1. 37* +-1. The timing pin. . "just slips in at 1. 35 and is tightening up at 1. 38. 5". .
That is not as accurate as the other shop would be, but for $75. 00 what the heck. I think I'll end up at VFI for a more accurate check in the future but for now I DID see a difference and the shop really tried hard to do it well using the pin method. It sure helped to clean up the cold start smoke and smoothness.

 

[AlK]

Hi Bush Wakr,

I think the shop that you are referring to is NW Fuel Injection. They did some work on my pump and injectores after somebody inadvertantly put some gas in the tank. The shop was recommended to me and I was very satisfied with their service. I am with you that a more acurate pump timing would be more desireable.

 

[BushWakr - RIP]

Yup thats the place. My bother and I have had great service from them. My bro. has a 92 standard cab 5sp.
That shop is not a performance dedicated shop but they do nice, careful work at a reasonble price.

 

[Old Nordby]

Al,

You are right, fairly simple to bleed. I suppose the lawyers say bleed only when cold, I've never done that. Yes, you are leaking fuel over hot engine blocks and manifolds, especially when high pressure bleeding while the truck is running. The dozen times I have done this (trying to debug injectors). Not sure what the pros here say, but I doubt it is too much hassle.

If the low pressure bleed does not fix your issue, consider cracking the fuel lines at the injectors while the truck is running, one at a time, until clear fuel is running from them. Wear goggles, and watch out for the fan when reaching around in there.

jon

 

[AlK]

Norby,
Thanks for the info. Started with the low pressure bleed then went on to the injetors. Very simple and straight forward. The first injector (closest to the fan) had some bubbles coming out. The smoke problem has improved, but I probably should consider getting the timing done.
---
Al

 

[Lil' Dog]

Big thumbs up to all in this post!!! #ad


I also did the injector bleed and found some bubbles in 3 out of the 6 and one of the fittings wasn't that tight. . Anyway, engine is much smoother and the smoke is reduced.

Thanks again guys!

J-eh