on cold starts one of my trucks is blowing blue. rev it and it misfires slightly and throws out a cloud of blue. give it about 5 minutes (sometimes less) and seems fine after that. it's got a little bit of a shake at idle and idle is right a 800rpm. thanks!

 

What's your ambient temperature during this?

At really low temperatures I'm pretty sure that it's normal, but the grid heaters should keep the blue smoke away at moderate temperatures.

Of course, since I'm from Southern California, my concept of "low" and "moderate" temperatures isn't exactly all that worthwhile...

I think that you're grid heaters are the most likely culprit. If they cycle, then maybe injectors or KSB? Just a sign of a middle-aged engine?

 

intercooled truck and temps can be 50's ish, the grids do cycle. i was thinking possibly injectors, getting them test/popped seems pretty expensive.

 

my '92 does the same thing. It has since I've had it. I just let it idle and warm up and it runs fine.

 

Most shops around here will test them for free, if you remove them and bring them in. Not that I really trust their opinion on whether they are good or not, but at least I can see the spray pattern and come to my own conclusions.

Daniel

 

Try adding a little timing.

 

That and check that your KSB is operating.

 

what does the exhaust smell like... is it very strong like unburnt fuel?

the last time my truck pumped out blue smoke and it was 50's the timing turned out to be too far advanced. however, you may have some other issue.

try diesel pro near fesslers lane for injection pop testing.

-brian

 

I agree, when the outside air temps are low, abouyt 30's and under your gonna seen the blue since the diesel is cold, once enough warm diesel gets pumped back through the return to heat the fuel in the tank, it usually goes away.

If your getting blue smoke in the 50's, has it been cold overnight? Say in the 30's or better and then the air has warmed since starting it, this would still leave the fuel cold since its under the truck and in the shade.

If your seeing it when its been a constant 50+ then yes you either have a slight injector leak or a timing issue.

 

SO how do you add timing to your Inj Pump and keep all fuel lines connected..
IE:
I can loosen all 2 of the bolts ob pump but the 3rd bolt on top of pump?
I can not get to it unless i take off the line on top of inj pump near front of engine..

Anyone have any tricks to loosen that bolt without disconnecting fuel lines?

Thanks

 

Patience and an S-wrench. Or just disconnect it. Its flexible enough that it will move out of your way by only disconnecting one side.

Brian

 

Micaiahfied, if it is running ruff when idling them maybe.....it an injector but if it is only running ruff when you try to bring it up to a hi idle, after a cold start then its eater the ksb or more likely,.........the timing need just a little bump in advance.

What you have described is the vary thing i worried a bout last year (popping ab banging and blue smoke!)
this winter them problem are gone! NO need to get crazy with the timing just a little will do.

I bump my timing up last summer a bout a1/16" and made the truck run much better all the way around!

Make sure the KSB is working right first!!!!!!!!.......then give it a bump! you will like it.

 

You can use a long extension and get that nut from back by the fuel filter.