6.2l rough start, white/blueish smoke

[07 grizzly700 BE]

So i have a 85 suburban 6.2l, and when i first got it it barely started in cold weather. So i changed the glowplugs to 60G's, the glow plug controller, cold weather motor oil (5w30), and the antifreeze.
But now it still starts very rough, except for when it is hooked up to the block heater.
So i checked the battery's and when i turn the key and the glowplugs start cycling, the voltage drops to 11v. Could it be the battery not having enough power to heat the glowplugs and turn the starter?( because the starter doesn't turn fast at all). Or could it be that the new 60G don't warm up long enough because of the stock controller? The controller is the thing with 2 terminals and 4 pins right? located behind the airfilter.
It does start, but it takes very long, and when it does, it runs rough and has A LOT of smoke.( white blueish)

Sorry for the long post, and thanks in advance guys,
Matt

 

[diesel4me]

Sounds like your '85 Burb and mine have a lot in common!...but mine starts hard because of many things,like the fact I'm pretty sure not all of my glow plugs work,and I'm not sure if the previous owner had used any "alternative fuels",it was set up for veggie oil ,but supposedly never was run on it...mine usually refuses to fire if its below 60 out unless you give it a whiff of ether,which I hate doing..

I'm surprised in Florida youd have to use a block heater!..
If all the glow plugs are working,it should start even in temps below 20 degrees without using the block heater--my '82 pickup will..however,using 60G glowpugs with the stock controller could be part of your issues,as they need to be "on" longer than the cintroller activates them for to be effective..both of my 6.2's have manual push buttons to energize the glow plugs...

Cranking speed is very important too--the faster you can get it to crank,the faster it'll start,as a diesel uses compression mostly to ignite the fuel,the glow plugs are just an aid--if its not spining fast enough,it'll start hard,if at all..the white and blue smoke you see after it finally started is unburned diesel fuel that built up in the cylinders and exhaust system,along with some motor oil that would account for the blue smoke..once it runs awhile it'll burn off and clear up....probably does the cylinders no justice,it can dilute the oil too...

I'd try jumping the glow plug relay for about 10 seconds and see if it starts any better,if it does then you'll be better off converting your glow plugs to a manual button rather than use the stock controller....I suspect the wiring harness going to my Subrbans glow plugs is gangrene and not letting full current get to all of them,on top of some of the glow plugs possibly not working...it'll be spring before I can do anything about that,right now the truck is buried under 2 eet of snow..

 

[07 grizzly700 BE]

Thanks for the advice.
Actually the suburban is from florida but i imported into Belgium, and here it's freezing almost everyday in winter.
How can i make the controller cycle the glowplugs for 10 seconds? Or do make them cycle through an external powersource? I think i will also check if all the glow plugs are receiving power, maybe one of the wires is cut or something. The battery's are definatley death too.

 

[Russell]

There is a mod you can do to the glow plug controller to change the glow time on your plugs, but I personally don't know if it is really required. I start my 6.2L in -20C all the time without much trouble running 60Gs and a stock controller.

All that said, does the smoke clear up when the engine begins to fire on all it's cylinders? Or does the smoke continue even once the engine has had a few minutes to warm up after starting to fire on all 8?

If it doesn't clear up, take some time and check all of the fuel lines, hoses and connections, as well as the integrity of your fuel pump. My 6.2L runs just like you describe when I have a leak in my fuel system and have air getting to the injection pump or when my electric fuel pump quits running for whatever reason and the injection pump is drawing fuel itself.

If it is just smoking when you first start it, that is totally normal. The bluish / white smoke you describe (more grey IMO) is un-burnt fuel. It isn't black because it isn't being burnt in the exhaust like when the engine is under a heavy load. My 6.2L always misses on a few cylinders for the first minute or so of running after cold starting it. Giving it 1/2 - full throttle will help improve cold starting as it puts more fuel in the cylinder, which results in more incompressible fluid in the cylinder, which increases the pressure in the cylinder and therfor also the temperature, which helps with starting. Once my engine is firing on all 8, and the engine is high idling, the smoke completely clears. Its once I drop off high idle that my engine starts to let a little bit of smoke out due to worn injection components.

 

[diesel4me]

Fully charged GOOD batteries are a must on any diesel,ones that are marginal will make for slow cranking and possibly not heat up the glow plugs enough...if they are old and weak,I'd ditch them....ditto ifor the starter,if its still cranking sluggishly,a gear reduction one will be an improvement ,ones from a later 6.5 bolt right on,but need a different front bracket to secure it to the block...I use 1/0 welding cable for my battery cables,the thicker they are the less voltage drop you get,and that makes a big difference in cold cranking power..

You'll probably have to search the diesel foum here for ideas on how to extend the amount of time the controller stays "ON",if you insist on keeping it stock--I think there was a thread about how to add a resistor to the wiring on it to make it stay energized longer..

I'd just convert it to a manual push button,myself...the 60G's wont overheat and swell up like the stock plugs can,even if left on too long...

....a plus is having them manually operated can act as a theft deterrent..it'd take someone with a good amount of knowledge about diesels to steal MY trucks,hell,I can hardly get them to start with the keys!...they would really have their hands full trying to figure out how to start it even if they did "hot wire" it!...

 

[blazinzuk]

As long as the smoke clears you are fine mine does exactly that and I have started it at 10F without it plugged in. I plug it in though cause it seems alot easier on the truck

 

[quinryan]

I just did the bypass routine (see earlier thread by me looking for help here) on my 82 Jimmy and (much to my surprise) it works better than the factory Glow-plug controller.

I just hold the button (it's a heavy-duty horn button, so it works like a dead-man switch) count to 5 or so, key the starter and it fires right up. Belgium must be a might colder than Colorado Springs, CO is these days, but the differance is incredible (something tells me that the now-dead GPC was dying anyway and not sending full juice to the plugs), and I have no doubt that it'd work for you, too.

All the other advice above is spot-on, too. Having a pair of fully charged, high-output batteries is the first thing. I run a pair with 1000 amps and 0-gauge cables.

Like the other guys said, the white/bluish-gray smoke is normal, too. If it makes white smoke after it's nice and warm than you may have a problem with coolant getting into the cylinders. Blue smoke after it's warmed up isn't all that uncommon either, though unwanted. It just means that some engine oil is being burned. These engines have some problems with head cracks, so it does happen.

2 questions for you: What did it cost to have a 'Burban shipped from Florida to Belgium (US military posting to NATO?) and what does diesel fuel go for there? All of a sudden we're paying ~$3.25- $3.30 for it in Southern Colorado. It's gone up .50 cents since August. War for cheap oil my @$$!

 

[07 grizzly700 BE]

Thanks guys. That is exactly what happens when i start it, some cylinders are not running smooth, a litlle vibration and smoke, but then after a while it starts running smooth and quits smoking. I will start with changing the batteries with optima's 1000 amps and see how that works out, if it doesn't start decently after that will do the manual override. I kinda like the fact that nobody would be able to steal it this way.
Diesel is less expensive then gas over here but still waaay more expensive then over in the US. Its 1.35eu/liter so thats like 7.36$ a gallon...
Its 2000$ for the shipment and then you have to pay customs, thats like 500eu and then 21% taxes, so it gets quite expensive because you still have to pass/pay inspection.

 

[AJMBLAZER]

Check your wiring at the GP controller. Mine had a break in the wire but if it was sitting correctly it made contact and read fine. Then when the truck shook at all it'd break contact and the GP's wouldn't glow. I finally replaced the GP controller harness and the last 8-10" of wiring and viola, problem solved.

To go with everyone the smoking is normal so long as it goes away. I drive a few older HMMWV's at work and some of them are downright scary at start up. 30 seconds later though they're purring clattering along happily grudgingly.

Uhm...maybe it's just me but I've never heard of using 5w30 as a winter oil in a diesel.